Primitive Photography: A Guide to Making Cameras, Lenses, and Calotypes [1 ed.] 9780240804613

Table of contents :
Cover
Primitive Photography: A Guide to Making Cameras, Lenses,and Calotypes
Copyright
Contents
Acknowledgments
Preface
1. The Film-Holder
Determining the Format
Tools Needed
Materials Needed
The Wet-Paper Process Film-Holder
The Dry, Waxed-Paper Film-Holder
Ground-Glass Substitutes
2. The Camera Body
Tools Needed
Materials Needed
The Sliding Box-Camera
The Folding-Camera
Wood Joining Procedure
3. The Lens
Lens Configurations
Physical Properties
Tools Needed
Materials Needed
The Singlet, or Landscape Lens
The Symmetrical Duplet, or Periscopic Lens
The Asymmetrical Duplet, or Portrait Lens
The Symmetrical Triplet
Lens Boards and Lens Caps
4. Calotype Paper Negatives
Chemicals Needed
Materials Needed
The Wet-Paper Process
The Dry, Waxed-Paper Process
5. Salt Prints by Development
Chemicals Needed
Materials Needed
Salt Processes
The Serum Process
Appendix: Sources of Supplies
Bibliography
Index

Citation preview

Primitive Photography A Guide to Making Cameras, Lenses, and Calotypes

Primitive Photography A Guide to Making Cameras, Lenses, and Calotypes

Alan Greene

First published 2002 This edition published 2013 by Focal Press 70 Blanchard Road, Suite 402, Burlington, MA 01803 Simultaneously published in the UK by Focal Press 2 Park Square, Milton Park, Abingdon, Oxon OX14 4RN Focal Press is an imprint of the Taylor & Francis Group, an informa business Copyright © 2002 by Taylor & Francis. All rights reserved. No part of this book may be reprinted or reproduced or utilised in any form or by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying and recording, or in any information storage or retrieval system, without permission in writing from the publishers. Notices Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility. To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein.

Library of Congress Cataloging-in-Publication Data Greene, Alan. Primitive photography : a guide to making cameras, lenses, and calotypes / Alan Greene. p. cm. Includes bibliographical references and index. ISBN 0-240-80461-9 (alk. Paper) 1. Photography—Equipment and supplies—Design and construction. I. Title. TR196 .G74 2001 771—dc21 20001040230 British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library.

ISBN 13: 978-0-240-80461-3 (pbk)

For All Photographers Present, Past, and Future

L’avenir de la photographie est tout entier dans le papier. Je ne saurais trop engager l’amateur à y diriger toute son attention et ses études. L’épreuve négative sur verre est plus fine, il est vrai; mais je crois que c’est là une fausse route, et que le but est d’arriver au même résultat avec le négatif sur papier. —   

•

Contents Preface

xi

Acknowledgments

xv

1

The Film-Holder 1 Determining the Format 2 Tools Needed 10 Materials Needed 11 The Wet-Paper Process Film-Holder 11 The Dry, Waxed-Paper Film-Holder 24 Ground-Glass Substitutes 34

2

The Camera Body 37 Tools Needed 40 Materials Needed 40 The Sliding Box-Camera 41 The Folding-Camera 63 Wood Joining Procedure 76

3

The Lens 81 Lens Configurations 81 Physical Properties 86 Tools Needed 99 Materials Needed 100 The Singlet, or Landscape Lens 100 The Symmetrical Duplet, or Periscopic Lens 108 The Asymmetrical Duplet, or Portrait Lens 116 The Symmetrical Triplet 125 Lens Boards and Lens Caps 131

4

Calotype Paper Negatives Chemicals Needed 140 Materials Needed 141

139

ix

The Wet-Paper Process 145 The Dry, Waxed-Paper Process 5

Salt Prints by Development Chemicals Needed 184 Materials Needed 186 Salt Processes 189 The Serum Process 203

170 181

Appendix: Sources of Supplies 211 Bibliography Index 219

x

215

•

Preface This book traces its origin to the spring of 1992, when I was a prospective graduate student taking a photographic criticism course. At one point during the course, the instructor made a remark that struck me deeply: he informed a class of aspiring young photo majors that photography would soon be supplanted by digital imaging. This prospect saddened me, for it was depressing to think that the mystery of darkroom chemistry might one day be abandoned for a television monitor connected to a mouse. Coinciding with this occurrence, I was more and more convinced that instead of evolving in recent years, photography had instead been devolving, due to the pressure of outside economic forces. First there was the industry-wide preference for 35 mm over large-format, irrespective of the fact that the latter offered more technical and perspective control. Then there was the introduction of auto-focus cameras. This was followed by the promotion of tabulargrain films and multi-contrast papers in tandem with the phasing-out of slower conventional films and graded papers. Given these occurrences, the movement towards digital imaging seemed little more than the crowning achievement of downward trends. More than ever before, I realized how completely at the mercy of market-driven forces fine-art photographers really were. I resolved that should the day ever come that manufacturers stopped making what I had always taken for granted—namely photographic film and paper—I would already know how to make photographs from scratch. Over the next year and a half, the difficult transition from thoughts to actions began. I read as much contemporary, technical writing as I could and came up with close to nothing. Alternative process and pinhole photography seemed to suggest partially viable responses to the problems I was facing, but nobody, it seemed, was concerned with making their own negatives. Lacking any real guide, I concluded that the answer lay in a return to photography’s origins, and that the method of making one’s own negative was to be found in mid-nineteenth-century technical writings. I had already been making paper negatives using single-weight paper loaded into an xi

8 ¥ 10 view-camera, so the calotype, or original paper negative process, appealed to me especially. I began to collect as many original accounts of the calotype process as I could find, studying them to arrive at a working method of my own. Thus, with photographic self-sufficiency as a goal, I attempted my first calotype paper negatives during the winter recess of the academic year 1993–94. The blackened pieces of paper that resulted were a severe disappointment, and were quickly thrown into the trash can. The time invested seemed immense, and I realized that given the burden placed upon me as a graduate student to produce finished work, I would have to postpone any further attempts until after I had finished school. Four years later, after having graduated, and after a bit more trial and error, I obtained what I would call my first success; but I soon discovered that in order to repeat this success I would have to construct my own film-holder. Having constructed a film-holder, I found myself wanting to build my own camera and lens as well. This appeared fairly daunting at first, but, ultimately, the equipment was not that difficult to make and I realized that a potential sub-genre of photography was waiting to be discovered in the landscape lens, along the lines of pinhole photography. So much for the events leading up to this book; the rest has been a matter of fine-tuning. Still, it remains that I should explain for whom this book has been written, and how they may approach using it. First and foremost, this book has been written for photographers who are seeking to express in novel and visually interesting ways what they find in the world around them. This includes anyone with a genuine interest in photography, and ranges from students fresh from their first experiences in the darkroom, to people wanting to expand the horizons of a self-absorbing hobby, to established, fine-art photographers. Secondly, this book has been written for those who are interested in the history of photography, and who are seeking to learn practical, hands-on approaches to mid-nineteenth century photographic processes. This includes students and teachers of photographic art history, as well as photographic print conservators, curators, and collectors. Thirdly, this book has been written for anyone who is concerned about photography’s survival as a fine-art medium, and who holds reservations about our society’s manifest trend towards computerization. Ultimately, this book has been written for those who are seeking handmade alternatives to the market forces driving technological change, or planned obsolescence motivated for its own sake. This book may either be used from start to finish or on a chapter by chapter basis according to the reader’s personal preferences and needs. Using it from start to finish, a student without the means to acquire expensive view-camera equipment might use the whole of the book to arrive at a very inexpensive way to continue making large-format photographs after graduating. An art-historian might use the entire book to arrive at a reasonable approximation of the xii

equipment and working procedures used by a mid-nineteenthcentury calotypist. Using it on a chapter by chapter basis, an established photographer, already owning a view-camera and lens, might prefer to by-pass the camera- and lens-making chapters, and concentrate on the film-holder, negative, and print-making chapters. Another example would be a hobbyist who has no interest in alternative processes, but wishes to concentrate upon the equipmentmaking chapters, in order to adapt these for conventional sheet-films and photographic papers. The equipment-making chapters need little more than a few basic hand-tools and a rudimentary knowledge of woodworking. Here I have chosen to emphasize ease of construction and functionality rather than patent displays of virtuosity. The negative- and print-making chapters need little more than patience and perseverance. Mistakes are bound to result at the start, but one quickly learns from them. Each chapter includes a listing of tools, materials, and chemicals needed, followed by a detailed listing of the procedures involved, taking the reader from start to finish. Each chapter is also accompanied by numerous illustrations, which serve as a complement to the text. All illustrations are done by me, unless otherwise indicated. All of the chapters begin with a brief introduction, placing the subject under consideration in its mid-nineteenth century context. The original English, French, and Belgian sources of my procedures are dutifully noted for those wanting to track them down. I have taken the liberty of translating any quotations originally written in French for the benefit of English-speaking readers. Most of these have never been translated before, but, in a few cases, an English translation may be found in the form of an Arno reprint edition. Unfortunately, these often paraphrase or mistranslate the original texts, so I have preferred to make a consistent practice of using and citing original authorities whenever possible. Throughout the book, the emphasis given to historical issues and sources will be treated as a point of departure rather than a nostalgic attempt to replicate the exact historical techniques and equipment. Fully aware of commonly practiced mid-nineteenth-century procedures, I have in some cases chosen to present lesser-known procedures that seem more applicable to the necessity of working with readily available, contemporary materials. Much has changed in the 150-odd years since these procedures last saw the light of day, and, as a practicing photographer, I must ultimately remain concerned with photography as a present living force. In taking this approach, I realize that photo-historians are bound to encounter a few inconsistencies. Take, for example, the recommendation of daguerrean and wet-collodion format sizes as standards of reference in cutting negatives, rather than Talbot’s wayward scissors-hand technique, or the attention given to Chevalier’s Photographe à verres combinés, rather than Petzval’s more popular portrait lens, or the preference shown towards Guillot-Saguez’s papernegative technique, over Talbot’s and Blanquart-Évrard’s celebrated xiii

procedures, or the presentation of salt prints by development, instead of the more commonly practiced printing-out technique. All of these run counter to the general consensus of modern photo-historians because they represent the exception rather than the rule. Here it is hoped that the notes I provide will serve as a source of reassurance that all of my examples are consistently grounded in mid-nineteenth century precedent and fact. What I have called primitive photography is a field that is open for us all to discover. Were I asked to define my use of the word “primitive,” I would have to say that it is not meant to connote what is naïve or rustic, but rather to connote the origin of a given entity.

xiv

•

Acknowledgments I would like to thank the following individuals for helping me at different times while this book was being made: Marie Lee, Jennifer Plumley, and Lilly Roberts, for editorial support and publishing assistance; Joel Snyder, for numerous suggestions and remarks concerning calotype paper negatives and salted paper processes; Mark Osterman, for advice and troubleshooting with regard to negativemaking operations; Richard Koolish, for suggestions and advice concerning the construction of homemade lenses; Jack Naylor, for allowing me to look at mid-nineteenth-century lenses in his personal collection; Ruud Hoff, for information concerning Chevalier’s Photographe à verres combinés; Roger Taylor, for comments and suggestions concerning mid-nineteenth-century calotype formats; Richard Fitzgerald, for comments regarding the construction of film-holders; Nicolas Le Guern, for allowing me to read his dissertation on the dry, waxed-paper process, and for verifying the thickness of midnineteenth-century French papers; Janet Heywood, for allowing me to turn the basement of the Mount Auburn Cemetery’s office into a temporary darkroom during the summer and fall of 1999; Laura Blacklow, for allowing me to use her darkroom and printing facilities as a back-up; Scott Able, for interrupting the Southworth Paper Company’s factory operations, in order to send me a special shipment of paper; Rebecca King, for allowing me to use the Cambridge Center for Adult Education’s computer facilities; Monique Johannet, for asking me to define the word “primitive”; Ken Jacobson and Will Stapp, for helping me to locate prints by Thomas Sutton; William Stoneman, Roger Eliot Stoddard, Evelyn Walker, and Thomas Ford, for granting me permission to reproduce images from the Houghton Library print collection; David Carpenter and Toni MacDonaldFein, for granting me permission to reproduce an image from the Fogg Art Museum print collection; Joe Struble and Janice Madhu, for granting me permission to reproduce an image from the George Eastman House print collection; and Raven Amiro and Martha King, for granting me permission to reproduce an image from the National Gallery of Canada print collection. xv

I would also like to thank my teachers, Bea Nettles, Linda Robbennolt, Ernie Scott, and Joe Squier, for advice and criticism given while I was a graduate student at the University of Illinois Urbana-Champaign, and Jim Dow, for teaching me just about everything I know about view-camera technique, and whose lectures on photo-history at the School of the Museum of Fine Arts first inspired me with a love of the medium. Finally, I would like to thank my wife, Virginie, for her constant support, patience, and enthusiasm concerning all of my photographic endeavors, and my father, for the example he has shown me.

xvi

1 The Film-Holder This chapter addresses the construction of film-holders for use with the calotype or paper-negative process. It begins with a survey of mid-nineteenth-century format possibilities drawn from original sources. This is followed by procedural demonstrations that show you how to build two types of film-holder designed to fit into the cameras presented in Chapter 2. The first is a double-glass film-holder, intended for negatives sensitized by the wet-paper process; the second is a lighter, travel film-holder, intended for negatives sensitized by the dry, waxed-paper process (see Chapter 4 for more on making negatives). Both types of film-holder are constructed using inexpensive hand-tools and materials, which are found in most hardware and art supply stores. They are designed to carry two sensitized negatives back-to-back and are easily modified to serve as focusing screens. They can also be used with modern-sheet films and photographic paper. Before moving further, it is necessary to explain why a filmholder should be built in the first place, since modern film-holders are available in a variety of format sizes. The main reason is because modern film-holders are constructed with a metal plate, which acts as a separating barrier between the negatives. When one uses handcoated paper negatives with modern film-holders, the silver nitrate on the negative inevitably migrates to the metal plate behind it. This residual silver nitrate combines with the metal in the film-holder and eventually causes staining problems with subsequent negatives loaded into the film-holder (see Figure 1.1). A film-holder with glass instead of metal eliminates this problem. Another reason for building one’s own film-holder pertains to the wet-paper process described in Chapter 4. By sandwiching the sensitized negatives between sheets of glass, the film-holder creates an effective barrier against evaporation, allowing the sensitized negatives to remain in a dampened state for an extended period of time. Yet another reason is that it is difficult to obtain film-holders in format dimensions exceeding 8≤ ¥ 10≤ or in custom sizes. 1

Figure 1.1 Why use a custom-built film-holder? In the sensitizing of this paper negative, a small amount of sensitizing solution accidentally leaked onto the backside. The sensitized negative was then loaded into a conventional 8≤ ¥ 10≤ film-holder, whereupon the metal in the barrier of the film-holder reacted with the silver nitrate on the backside of this negative, causing the linear stain. Had the barrier been made of glass, which is inert (chemically unreactive), the stain would have been hardly noticeable.

DETERMINING THE FORMAT In order to build a film-holder, you must decide upon the format, or two-dimensional surface area, of the photograph you wish to make. This decision is important because all other equipment is to be affected by it, from the size of the camera to the focal length of the lens. Since you will be making contact-prints rather than enlargements, the size of your negatives will have to be the same size as the image you intend to make. Far from being limited in this regard, you have the potential to realize any format size imaginable. Perhaps it is a circular or square image format you want to make rather than a rectangle; paper negatives allow you to cut them down to any size or shape. As such freedom may lead to confusion, it is better to lay down a few guidelines first, based upon historical precedents (see Figure 1.2). Given that calotype formats were essentially customized, with no two image sizes remaining the same, it may be asked why I feel it 2

Figure 1.2A and B Two midnineteenth-century film-holders. (A) Reprinted from W. [Marcus] Sparling, Theory and Practice of the Photographic Art (1853; reprint, New York, 1973), 45, fig. 55. (B) Reprinted from E. de Valicourt, Nouveau manuel complet de photographie, (Paris, 1862), v.1, fig. 20.

A

B

necessary to establish a set of format standards from the start. There are a number of reasons for this decision:

• It is helpful to have a clear-cut format in mind when viewing a scene or composing an image. • The dimensions of the cameras (discussed in Chapter 2) are determined by a combination of the negative format, filmholder size, and lens focal length. • The angle of view and focal length of the lenses (discussed in Chapter 3) are determined by the diagonal measurement of the format used. • Apart from the earliest calotype practitioners (such as Talbot, Bayard, and Channing), there is every reason to suppose that later calotypists were making negatives in relation to the prevailing daguerreotype and collodion formats of the day. These reasons being given, it remains my intention that the formats considered below be taken in a flexible sense. Once a nega3

tive has been made, do not hesitate to depart from the original format if you think it will improve the image. Remove as much negative information as you deem necessary, cutting it down roughly with scissors or painstakingly with a sharp utility knife and straight-edge, or, if necessary, tearing it with your bare hands. On the other hand, leaving marginal stains, rough edges, and torn corners may enhance the quality of a photograph. In such cases, you might reconsider automatically trimming them away.

Calotype Format Standards Let us briefly survey the historical evolution of calotype formats, from the dawn of the calotype era in the 1830s to its close in the early 1860s. Calotype photography is often associated with its inventor, William Henry Fox Talbot, a British scientist who began experimenting with light-sensitized paper in the 1830s.1 As evinced from his earliest photographs, Talbot was in the practice of cutting his negatives with a pair of scissors or a dull knife in order to remove unwanted chemical stains and torn corners. At times, this led to rather irregular shapes and rough edges, very different from the perfectly rectangular images we associate with the photographic image today. Since Talbot had no established precedent or industry standard to draw from, his negative formats tended to be unique, based upon whatever wooden box and lens combinations he happened to have on hand, which were more or less obtained from local cabinetmakers and his friends, who were scientists using microscopes and telescopes. Untrained as a visual artist, he thought nothing of aiming his camera up at an acute angle to photograph an architectural detail.2 Today, we have come to accept this point of view, but in Talbot’s day it was to depart from one of the cardinal rules governing the theory of perspective, which insisted that all the vertical lines in a scene be represented as running parallel to the picture frame. By the early to mid-1840s, Talbot’s imagery appears to have changed.3 Gone are the wild formats and ragged cuts of earlier years. Vertical perspective lines are running parallel and all torn corners are neatly trimmed. The images are much more formal. Perhaps this was due to his continued experience with the process or to his resultant associations with people who had formal artistic training. Perhaps this was also due to the competing example of the daguerreotype, to which the calotype remained more or less an anomaly. There also was his desire to make the calotype an industrialized printing process in its own right. For whatever reason, a standard, perhaps only of precision, was starting to evolve in his work by the early to mid-1840s. By the late 1840s, his interests appear to have moved away from the calotype. It is worth noting that Talbot’s departure from the calotype coincides with its large-scale adoption by the French. Starting in 1847, with treatises on the paper-negative process being published by LouisDésiré Blanquart-Évrard and A. Guillot-Saguez, and culminating 4

Table 1.1

Daguerrean-Plate Dimensions (France, ca. 1843–44)

Sixth-plate 72 mm ¥ 82 mm (2-7/8≤ ¥ 3-1/4≤) Quarter-plate 82 mm ¥ 108 mm (3-1/4≤ ¥ 4-1/4≤) Half-plate 121 mm ¥ 162 mm (4-3/4≤ ¥ 6-3/8≤) Whole-plate 164 mm ¥ 216 mm (6-7/16≤ ¥ 8-1/2≤) — 240 mm ¥ 320 mm (9-7/16≤ ¥ 12-5/8≤) Sources: Charles Chevalier, Mélanges photographiques (Paris: [self-published], 1844), [page 3 of an advertising catalogue]; and N[öel]-P[aymal] Lerebours, Traité de Photographie, 4th ed. (Paris: Lerebours, 1843), 52, 71.

in 1851, with the publication of the dry, waxed-paper process by Gustave Le Gray, French practitioners introduced a number of changes to Talbot’s original techniques.4 One such change involved a more standardized approach to the formatting of paper negatives. I believe that this was due to the widespread prevalence of daguerreotype photography, which quickly had evolved to an industrialized level, necessitating the standardization of equipment and format sizes.5 Rather than invent the calotype process all over again, French practitioners approached it with a pre-existent knowledge of the daguerrean process, using and modifying available daguerrean equipment and formats, which they cited as points of reference. Examples of this can be found as early as 1847 in the technical literature; Guillot-Saguez made the following remarks concerning his preliminary negative-making techniques: “The sheet of paper having been trimmed two centimeters longer than the ground-glass of the camera is plunged for a minute in the solution. . . .”6 Continuing his description, he added that a tablespoon’s worth of sensitizing solution was enough “. . . for a sheet of paper that does not surpass what is called whole-plate.”7 Also noteworthy is that Guillot-Saguez listed himself in a Parisian trade dictionary as a daguerreotypist, specializing in portrait daguerreotypes on paper.8 References to daguerrean plate formats on the part of French calotypists are not confined to Guillot-Saguez alone. For example, they can be found in the remarks of Le Gray. Describing the necessary lenses to be used with his modifications of the calotype process, he wrote, “With a whole-plate lens for monuments and a half-plate lens for portraits, the amateur has all that he needs.”9 About a modification of a simple lens designed for whole-plates, to which he added a second lens element, he remarked, “. . . I obtain an image from quarter to third-plate, excessively bright and with a very short focus that gives me an extraordinary rapidity.”10 What is important in these quotations are the references to whole-plate, half-plate, and quarter-plate, which were common daguerrean formats at the time (see Table 1.1). In viewing a scene with cameras and lenses primarily intended for daguerreotypes, a calotype photographer would have tended to use the daguerrean format as a point of reference, trimming the resultant paper negative to whatever dimension worked best for a given image. Take, for 5

Table 1.2 Collodion and Calotype Formats (England, 1855) Collodion

Calotype

3≤ ¥ 4≤ — 4≤ ¥ 5≤ 4≤ ¥ 5≤ 5≤ ¥ 6≤ — 6≤ ¥ 7≤ 6≤ ¥ 7≤ 7≤ ¥ 9≤ 7≤ ¥ 9≤ 10≤ ¥ 12≤ 10≤ ¥ 12≤ Source: Horne and [W.H.] Thornthwaite, Horne & Thornthwaite’s Descriptive Catalogue of Scientific Instruments, 4th ed. (London: [self-published], 1855), pt. 2, 98–99, 117–20.

example, the calotype work of Henri Le Secq. All of his portraits vary considerably in actual size, and yet many remain consistently within range of 80 mm ¥ 110 mm, or quarter-plate size. Similarly, many of his architectural studies measure in the range of 240 mm ¥ 320 mm.11 When we note that this dimension was a large daguerrean format of the time, it seems to suggest that he was trimming his negatives in relation to this standard, or one close to it. Returning to Britain, one finds a number of Talbot’s successors making calotypes in an increasingly standardized fashion. An early example of this, dating to the mid-1840s, can be found in Antoine Claudet’s London photographic studio, which advertised the making of daguerreotype and calotype portraits, with the different procedures’ format dimensions being listed side by side.12 Similarly, many of the portraits made in the mid-1840s by the Scottish calotypists Hill and Adamson measure just under 6-1/2≤ ¥ 8-1/2≤, suggesting a daguerrean whole-plate dimension from which they could have been trimmed down.13 John Muir Wood’s individual and group portraits from the late 1840s to the early 1850s also at times seem close to quarter-plate and half-plate dimensions.14 By the mid-1850s, the prevalence of the daguerreotype process had been largely eclipsed by the arrival of the collodion process in 1850–51. Coincidentally, the standardization of calotype formats came into full flower in the mid-1850s. This can be evinced from an examination of photographic equipment catalogues from the period. For example, a Horne and Thornthwaite catalogue from 1855 advertised photographic equipment that could be used with both the collodion and calotype processes. In addition, the catalogue gave separate listings for the film-holders used with the different processes, which nevertheless maintained corresponding format dimensions (see Table 1.2). 15 Horne and Thornthwaite’s format listings are confirmed by Thomas Sutton, an English calotypist living on the island of Jersey, who wrote a calotype manual in 1855. In his discussion of three lenses to be used in making paper negatives, Sutton wrote, “the first takes 6

Table 1.3 Portrait Lens Focal Lengths and Diameters, with Specified Format Sizes (England, ca. 1855) Focal Length (Rear Element)

Lens Diameter

Format

4≤ 1-3/4≤ 3≤ ¥ 4≤ 6-1/2≤ 3-1/2≤ 3≤ ¥ 4≤ (rapid) 6≤ 2-1/2≤ 4≤ ¥ 5≤ 7-1/2≤ 2-1/2≤ 4≤ ¥ 5≤ (larger portraits) 8≤ 3-1/4≤ 4-3/4≤ ¥ 6-1/2≤ 12≤ 4-1/2≤ 6-1/2≤ ¥ 8-1/2≤ Source: Thomas Sutton, The Calotype Process: A Hand Book to Photography on Paper (London: Joseph Cundall, 1855) [unpaginated catalogue advertising Ross lenses].

Table 1.4 Landscape Lens Focal Lengths and Diameters, with Specified Format Sizes (England, ca. 1855) Focal Length

Lens Diameter

Format

9≤ 2≤ 5≤ ¥ 6≤ 12≤ 2-1/2≤ 6-1/2≤ ¥ 8-1/2≤ 15≤ 3≤ 8≤ ¥ 10≤ 18≤ 3-1/2≤ 10≤ ¥ 12≤ 20≤ 4≤ 12≤ ¥ 15≤ 25≤ 5≤ 16≤ ¥ 18≤ 30≤ 6≤ 20≤ ¥ 22≤ 35≤ 7≤ 22≤ ¥ 24≤ 40≤ 8≤ 24≤ ¥ 26≤ Source: Thomas Sutton, The Calotype Process: A Hand Book to Photography on Paper (London: Joseph Cundall, 1855) [unpaginated catalogue advertising Ross lenses].

a picture twelve inches by ten inches, the second nine inches by seven inches, and the third four inches by three inches.”16 Sutton’s remarks appear contradicted by the inclusion of a catalogue at the end of the manual, which advertised Ross photographic equipment with slightly different format sizes (see Tables 1.3 and 1.4). If we move to the late 1850s, we find in the technical writings of the Belgian Désiré van Monckhoven a remarkable thoroughness and attention to detail.17 Like his predecessors, Guillot-Saguez and Le Gray, Monckhoven fell into the routine of describing the calotype negative-making process in relation to daguerrean and collodion plate sizes. For example, in an 1857 calotype manual, he described how a dry, waxed-paper negative is to be cut slightly larger than the desired end result, writing, “It is necessary that [a sheet of paper] start out two centimeters larger than the size one wants to obtain from the camera. . . . For ease of comparison, we will use a dimension generally employed, that of the whole-plate of eighteen by [twentythree] centimeters, which is to be cut to a larger dimension of twenty-two by twenty-seven centimeters.”18 Still more important was a chart he included in the manual, listing lens focal lengths and diameters, viewed in relation to standard format sizes (see Table 1.5). 7

Table 1.5 Calotype Formats with Lens Focal Lengths and Diameters (France, 1857) Format

Focal Length (Rear Element?)

Lens Diameter

Quarter-plate 100 mm 44 mm Half-plate 180 mm 57 mm Whole-plate 250 mm 81 mm 250 mm ¥ 320 mm 500 mm 81 mm 300 mm ¥ 400 mm 600 mm 108 mm Source: D[ésiré] van Monckhoven, Méthodes simplifiées de photographie sur papier (Paris: Marion, 1857), 48.

Table 1.6 French Glass-Plate Dimensions with Corresponding Diagonals (1863) Plate Size

Format

Format Diagonal

— 75 mm ¥ 92 mm (3≤ ¥ 3-5/8≤) 119 mm (4-5/8≤) Quarter-plate 95 mm ¥ 125 mm (3-3/4≤ ¥ 5≤) 157 mm (6-1/8≤) — 120 mm ¥ 160 mm (4-3/4≤ ¥ 6-1/4≤) 200 mm (7-7/8≤) Half-plate 136 mm ¥ 180 mm (5-3/8≤ ¥ 7-1/8≤) 226 mm (8-7/8≤) Whole-plate 180 mm ¥ 240 mm (7-1/8≤ ¥ 9-7/16≤) 300 mm (11-7/8≤) — 210 mm ¥ 270 mm (8-1/4≤ ¥ 10-5/8≤) 342 mm (13-1/2≤) — 250 mm ¥ 320 mm (9-7/8≤ ¥ 12-5/8≤) 406 mm (15-15/16≤) — 270 mm ¥ 350 mm (10-5/8≤ ¥ 13-3/4≤) 442 mm (17-3/8≤) — 300 mm ¥ 400 mm (11-3/4≤ ¥ 15-5/8≤) 500 mm (19-9/16≤) — 400 mm ¥ 500 mm (15-5/8≤ ¥ 19-5/8≤) 640 mm (25-1/16≤) Source: Adapted from D[ésiré] v[an] Monckhoven, Traité général de photographie, 3rd ed. (Paris: Victor Masson, 1863), 139.

Once again, these are given along the lines of daguerrean and collodion glass-plate format sizes: quarter-plate, half-plate, whole-plate, and so on. Although Monckhoven stated that a whole plate was 180 mm ¥ 230 mm, it remains unfortunate that he did not specify the half-plate and quarter-plate dimensions in the 1857 manual. To rectify this, we must consult an 1863 general manual of photography, in which he defined these terms completely.19 There he published two charts, one listing French glass-plate formats and the other listing English glassplate formats (see Tables 1.6 and 1.7). The fact that these were given with the collodion process in mind, rather than the calotype process, need not give too much concern, since he also made the following remarks with regard to a film-holder used with paper negatives: “It is obvious that in operating in this way [i.e., with calotype negatives], one is able to use the same film-holders that are used with collodion. . . .”20 With Monckhoven, our survey of mid-nineteenth-century format possibilities draws to a close. This is partly because the calotype had fallen into disuse by the early 1860s and partly because the charts Monckhoven published were so comprehensive as to eliminate 8

Table 1.7 English Glass-Plate Dimensions with Corresponding Diagonals (1863) Plate Size

Format

Format Diagonal

— 2≤ ¥ 2-1/2≤ (50 mm ¥ 63 mm) 3-3/16≤ (80 mm) — 2-3/4≤ ¥ 3-1/4≤ (69 mm ¥ 82 mm) 4-1/4≤ (107 mm) Quarter-plate 3-1/4≤ ¥ 4-1/4≤ (82 mm ¥ 108 mm) 5-3/8≤ (136 mm) — 4≤ ¥ 5≤ (102 mm ¥ 127 mm) 6-3/8≤ (163 mm) Half-plate 4-3/4≤ ¥ 6-1/2≤ (120 mm ¥ 165 mm) 8-1/16≤ (204 mm) Whole-plate 6-1/2≤ ¥ 8-1/2≤ (165 mm ¥ 216 mm) 10-11/16≤ (272 mm) — 8≤ ¥ 10≤ (203 mm ¥ 254 mm) 12-13/16≤ (325 mm) — 10≤ ¥ 12≤ (254 mm ¥ 306 mm) 15-5/8≤ (398 mm) — 12≤ ¥ 15≤ (306 mm ¥ 383 mm) 19-3/16≤ (490 mm) — 16≤ ¥ 18≤ (408 mm ¥ 458 mm) 24-1/16≤ (613 mm) Source: Adapted from D[ésiré] v[an] Monckhoven, Traité général de photographie, 3rd ed. (Paris: Victor Masson, 1863), 139.

the need for any other. In comparing Table 1.6 to Table 1.7, we see that French plate dimensions are slightly larger than their English counterparts. This disparity is probably due to the different systems of measurement, compounded by a practical rounding off to the nearest centimeter or fraction of an inch. Also, in comparing Table 1.6 to Table 1.1, we note that French plate dimensions in the early 1860s were larger than in the early 1840s, and that English plate dimensions in the 1860s remain closer to the original daguerrean dimensions. Ultimately, it seems that an absolute standard concerning mid-nineteenth-century formats cannot be reached, since it never existed. Therefore, we can only refer to mid-nineteenth-century calotype formats in a relative, or ideal, sense.

Using the Format Charts Given the relative nature of the formats in question, any of the tables listed above could serve as the basis for designing equipment. Nevertheless, because Tables 1. 6 and 1.7 offer the widest selection of format possibilities, combined with only slight variances with the other tables, they have been chosen as the basis of design for all of the equipment presented in this book. For reasons of clarity, I will concentrate upon two format dimensions: the first being the English whole-plate, measuring 6-1/2≤ ¥ 8-1/2≤, and the second being the French landscape dimension, measuring 210 mm ¥ 270 mm. Should you wish to cut your negatives down to another size or format, or design equipment for another format than what is given in the construction examples, Tables 1.6 and 1.7 are suggested as a starting point. Included in Tables 1.6 and 1.7 are the diagonal measurements for each format. These play an important role in determining the design parameters for the cameras and lenses described in Chapters 9

2 and 3. By determining the diagonal measurement of the format in question, one arrives at the focal length of a lens with a normal angle of view for that format. Any lens focal length shorter than the diagonal yields an angle of view ranging from wide-field to wide-angle, and any lens focal length longer than the diagonal yields an angle of view that is narrow-angle (see Chapter 3). The diagonal of the format may be found by drawing the format out on a piece of paper and measuring the distance between the opposite corners. It is more accurately determined by applying the Pythagorean theorem, which states that the diagonal of the rectangle should always equal the square root of the sum resulting from the square of one side of the rectangle added to the square of the adjacent side of the rectangle. For example, to find the diagonal of a format measuring 210 mm ¥ 270 mm, one starts by squaring the dimensions of the format: 210 ¥ 210 = 44,100, and 270 ¥ 270 = 72,900. The two resultant numbers are then added together to find the total: 44,100 + 72,900 = 117,000. Finally, the square root of 117,000 is taken, which equals 342.05263. This result can be rounded off to a diagonal measuring 342 mm.

TOOLS NEEDED In order to build the film-holders, you will need a number of hand-tools. All of them are quite common and can be purchased in most hardware and art-supply stores. These are listed below:

• A utility-knife with blades • A pencil • A cork-backed, metal straight-edge with inch and millimeter • • • • • • • • • • • • • • • • • 10

markings A plastic triangle or T-square A modeler’s razor saw, designed to cut wood (16 teeth per inch) A modeler’s miter box 3 to 9 C-clamps (1-1/2≤ to 2≤ opening) A 90° corner-clamp (the cheap, aluminum ones work fine) A portable power-drill A 1/8≤ drill-bit A mallet (or a hammer and a small block of wood) A handheld, orbital sander A dust-mask (to wear while sanding) Safety glasses (to wear while sanding) A putty knife A 1≤-wide, hog-hair or synthetic bristle brush A no. 5, ox-hair or synthetic bristle brush Rubber dishwashing or latex examination gloves (to wear while painting) A black magic marker (such as a Sharpie“ “Fine Point”) A silver marking pen

MATERIALS NEEDED Listed below are the materials needed to make film-holders. Once again, most of these can be found in hardware and art-supply stores and require little further explanation. Luan, a thin plywood used in covering hollow-core doors, can be purchased from most lumberyards. The materials needed are as follows:

• Luan“ plywood, 1/8≤ thick (usually sold in 4¢ ¥ 8¢ sheets) • A number of 2¢ or 3¢ lengths of basswood frame-stock, of • • • • • • • • • •

varying dimensions (final lengths are cut to the dimensions specified in the procedural steps) 1 to 6 sheets of single-strength window-pane glass (cut to the dimensions specified in the procedural steps) Wood glue (Titebond“ is recommended) A 1/8≤ wooden dowel (comes in 3¢ or 4¢ lengths) 60-grit and 150-grit sandpaper A small jar of wood putty A quart of flat-black, enamel paint A pint of turpentine (for cleaning brushes after painting) Newspaper A sheet of glassine paper 1/4≤ to 1/2≤-wide cellophane tape (such as Scotch Magic Tape“)

THE WET-PAPER PROCESS FILM-HOLDER The 8≤ ¥ 10≤ film-holder described below is intended for use with wet-paper process negatives, trimmed down to a final, wholeplate size of 6-1/2≤ ¥ 8-1/2≤. It is designed to hold two negatives back-to-back, which are separated by a piece of rubylith film and sandwiched between two identical pieces of glass. The reason for the rubylith film is to prevent the passage of light from one negative to the other during exposure. The reason for the sandwiched glass is to prevent the negatives from drying out too quickly, since they need to be exposed while in a dampened state (see Chapter 4 for more on making the negative). This film-holder has not been designed from any direct source, although Talbot and Blanquart-Évrard are usually cited as originators of the double-glass design. Rather, the film-holder described here is born out of my frustration with the stains caused by the metal plate in modern film-holders (see Figure 1.1). Starting from the vague hints of a film-holder given in Thomas’ alleged account of Frédéric Flachéron’s process, I arrived at my own design through trial and error.21 This film-holder is primarily intended for wet-paper process negatives, but may be used to make dry, waxedpaper negatives, with absolutely no changes at all being required. It may be adapted for use with modern sheet-films and photographic paper by substituting a thin sheet of black card-stock for the rubylith film. And should you prefer to build the film-holder for use with a 11

modern 8≤ ¥ 10≤ view-camera, the essential design can be modified during construction to achieve a slimmer version of the film-holder. Simply follow the parenthetical notes given at the end of certain procedural steps. The design specifications given below may be modified for use with larger or smaller format cameras. All that you need to do is adjust the lengths of the basswood frame-stock, and the dimensions of the glass and Luan as specified, to match any given format size and lens focal length. All other dimensions and procedural steps should remain nearly the same. Note: with careful measurement, the film-holder and camera body can be built separately. Nevertheless, it is recommended that the construction of the film-holder and camera occur in tandem with each other (see Chapter 2). This is to ensure accuracy of fit, with regard to the sanding of the film-holder and camera body, and the placement of the light-traps on the film-holder. With this in mind, I have divided the construction procedures given below into two major sections. The first section, or initial construction procedure, pertains to the main-frame of the film-holder. Ideally, this should occur in tandem with the construction of the front and rear sections of the sliding box-camera. Once the fit of both component parts has been verified, the second section, or final construction procedure, may proceed independently. (If you are building a film-holder for use with a modern 8≤ ¥ 10≤ view-camera, you may ignore these remarks and proceed to the finishing procedures directly, since the fit of the film-holder and light-traps is not an issue.)

Initial Construction Procedure The initial procedure for constructing the wet-process filmholder is given below. For ease of comprehension, this has been divided into five subsections: cutting wood to size, constructing the bottom section, constructing the side sections, assembling the mainframe, and finishing and sanding the main-frame.

Cutting Wood to Size The width and thickness dimensions of basswood frame-stock are previously cut by the manufacturer and sold in the form of 2¢ and 3¢ lengths. In this way, two or more specified lengths may be obtained from an original 2¢ or 3¢ length. With this in mind, cut the basswood frame-stock to the following specified lengths using a modeler’s razor saw and miter box:

• Four 3/4≤ ¥ 1/8≤ ¥ 9-1/16≤ (Note: if you are building a film-holder for use with a modern 8≤ ¥ 10≤ view-camera, this dimension should be 3/4≤ ¥ 1/16≤ ¥ 9-1/16≤.) • Eight 3/4≤ ¥ 1/8≤ ¥ 9-1/2≤ (Note: if you are building a film-holder for use with a modern 8≤ ¥ 10≤ view-camera, this dimension should be 3/4≤ ¥ 1/16≤ ¥ 9-1/2≤.) 12

• • • • • •

Two 1/2≤ ¥ 1/8≤ ¥ 8-1/16≤ Four 1/2≤ ¥ 1/8≤ ¥ 8-9/16≤ Four 1/2≤ ¥ 1/8≤ ¥ 12-1/4≤ One 1/2≤ ¥ 1/4≤ ¥ 8-1/16≤ Two 1/2≤ ¥ 1/4≤ ¥ 12-1/4≤ Two 1/4≤ ¥ 1/4≤ ¥ 9-9/16≤ (Note: if you are building a film-holder for use with a modern 8≤ ¥ 10≤ view-camera, these are not needed.) • Two 3/8≤ ¥ 1/4≤ ¥ 1≤ (Note: if you are building a filmholder for use with a modern 8≤ ¥ 10≤ view-camera, these are not needed.) • Four 2≤ ¥ 1/8≤ ¥ 9-1/16≤ (Note: wood that is wider than the miter box may still be cut with it. First mark the line to be cut in pencil, then lean the wood into the miter box, so that the saw can line up with one of the slots in the miter box and the line marked on the wood. Also note that if you are building a film holder for use with a modern 8≤ ¥ 10≤ view camera, this dimension should be 2≤ ¥ 1/16≤ ¥ 91/16≤.) • One 3≤ ¥ 1/4≤ ¥ 8-1/16≤ The diameters of basswood dowels are also determined by the manufacturer and sold in the form of 3¢ and 4¢ lengths. As very little dowel material will be used in the construction of the film-holder, one 3¢ length of a 1/8≤ dowel will be sufficient. Cut the dowel with a utility knife, rather than a saw, in order to avoid tearing the ends of the dowel. Mark a line on the length of the dowel where the intended cut is to be made, and then roll the dowel beneath the razor’s edge at the indicated mark, gradually increasing the pressure of the utility knife until the cut is made. Using this suggested cutting method, cut the following basswood dowel sections:

• Six 1/8≤ ¥ 1-1/8≤ (Note: if you are building a film-holder for use with a modern 8≤ ¥ 10≤ view-camera, this should be 1/8≤ ¥ 15/16≤.)

Constructing the Bottom Section Taking the four 3/4≤ ¥ 1/8≤ ¥ 9-1/16≤ pieces, the two 1/2≤ ¥ 1/8≤ ¥ 8-1/16≤ pieces, and the individual 1/2≤ ¥ 1/4≤ ¥ 8-1/16≤ piece, start to make the bottom section of the film-holder, gluing the basswood pieces together according to the indicated diagram (see Figure 1.3). Spread the glue out evenly, making sure that the pieces are centered and flush with regard to what will be the bottom edge of the film-holder. Use three C-clamps to hold the pieces of wood in place—one placed in the middle and the other two at each end (see Figure 1.4). Remove any excess glue before it dries completely by sliding scrap pieces of basswood into the grooves and along the edges. Allow the section to dry for a few hours with the C-clamps in place. 13

Figure 1.3 Bottom section. 8≤ ¥ 10≤ wet-process film-holder. Top and front views.

1≤ 8 1≤ 8 1≤ 1≤ 8 4

1 ≤

1≤ 2

3≤ 4

9 16

1≤ 8 1≤ 8 1≤ 8

1 ≤

1≤ 2

8 16

1≤ 2

Constructing the Side Sections Taking four 3/4≤ ¥ 1/8≤ ¥ 9-1/2≤ pieces, two 1/2≤ ¥ 1/8≤ ¥ 12-1/4≤ pieces, and one 1/2≤ ¥ 1/4≤ ¥ 12-1/4≤ piece, start to make one of the side sections of the film-holder by gluing the basswood together, according to the indicated diagram (see Figure 1.5). Spread the glue out evenly, making sure that the pieces are in the right location and flush with regard to what will be the side edge of the filmholder. Use three C-clamps to hold the pieces of wood in place—one placed in the middle and the other two at each end (see Figure 1.4). Remove any excess glue before it dries up completely by sliding scrap pieces of basswood into the grooves and along the edges. Allow to dry for a few hours with the C-clamps in place. Make the other side section in exactly the same way, using the remaining four 3/4≤ ¥ 1/8≤ ¥ 9-1/2≤ pieces, the remaining two 1/2≤ ¥ 1/8≤ ¥ 12-1/4≤ pieces, and the remaining 1/2≤ ¥ 1/4≤ ¥ 12-1/4≤ piece. Both side sections are identical. Figure 1.4 Gluing up a side section of the film-holder. Note the use of scrap pieces of basswood between the C-clamps and glued section in order to prevent marring the film-holder. Also shown is a hobbyist’s miter box and razor saw.

Assembling the Main-Frame Once the bottom and side sections have dried, remove the Cclamps and trim away any excess glue with a utility knife. Check the fit of the three sections by putting them together according to the diagram, along with the four 2≤ ¥ 1/8≤ ¥ 9-1/16≤ pieces that form the top of the main-frame (see Figure 1.6). Everything should fit closely, with only small gaps or protrusions (up to 1/16≤ is acceptable). Once the fit has been verified, take the sections apart and proceed to assemble the main-frame as follows (see Figure 1.7): 1. Line the exposed, bottom area of one of the side sections with glue. Fit this to the corresponding area of the bottom section and place the two joined sections into a 90° cornerclamp. Tighten the clamp until both sections are firmly held, double-checking to make sure that the angle formed is square.

14

Finishing and Sanding the Main-Frame Once the glue in the main-frame has dried, the following steps bring the assembly of the main-frame to completion (see Figure 1.8): 1. Fill any gaps on the exterior of the main-frame with putty using a putty knife. Allow to dry. 2. With an orbital hand-sander, sand the two exterior faces of the main frame using 60-grit sandpaper. Follow the grain of the wood, sanding until the faces are even and the dowel ends are flush. ALWAYS WEAR SAFETY GLASSES AND A DUST MASK WHEN SANDING. ALWAYS SAND IN AN AREA WHERE THERE IS ADEQUATE VENTILATION. 3. Sand the side, bottom, and top edges of the main frame until they are even and square. Edge sanding is most easily achieved by taping a sheet of 60-grit sandpaper to a worktable or hard surface, and then passing the edges of the

1 8 ≤ ≤ 1

1≤ 8

1≤ 4 1≤ 8

1≤ 8 1≤ 8

3≤ 4

9

1 ≤ 2

12

1 ≤ 4

2≤

8

2. While the sections are gluing, drill a 1/8≤ pilot hole in the area where the two sections overlap and join, as indicated in the diagram (see Figure 1.6). 3. Add a drop of glue to the drilled hole from step 2, followed by lining one of the 1/8≤ ¥ 1-1/8≤ dowels with a small amount of glue as well. Taking a mallet, lightly tap the dowel into the hole (if you use a hammer, place a block of wood in between the hammer and the dowel in order to soften the blow). When the dowel is completely in the joint, approximately 1/16≤ of the dowel should stick out on both sides of the main-frame. This will be sanded later. 4. Remove the wood from the corner-clamp and repeat steps 1 to 3, attaching the other side section to the bottom section in exactly the same way. Remove the wood from the corner-clamp and wipe off the excess glue from both joints. 5. Taking the four 2≤ ¥ 1/8≤ ¥ 9-1/16≤ pieces, glue them into place at the top of one of the side sections, again using the 90° corner-clamp. Once the pieces are lined up with one side section, and the clamp is holding everything secure, drill two 1/8≤ pilot holes, where the top pieces overlap the side section, as indicated in the diagram (see Figure 1.6). 6. Repeat step 3, installing a 1/8≤ ¥ 1-1/8≤ dowel into each of the drilled holes. Once the dowels are in place, remove the wood from the corner-clamp. 7. Repeat steps 5 and 6, joining the top pieces to the other side section. Remove the wood from the corner-clamp and allow the main-frame assembly to dry for a few hours.

1≤ 2 1≤ 4 3≤ 4

Figure 1.5 Side section. 8≤ ¥ 10≤ wet-process film-holder. Side and front views.

15

Figure 1.6 Initial assembly of the main-frame. 8≤ ¥ 10≤ wet-process filmholder. Front and side views.

1 ≤

(Dowel)

9 16

1≤

(Dowel)

1≤ 8

1≤ 1≤ 2

1≤ 2

2≤

1≤

1≤ 8

1≤ 2

1≤ 2

1≤ 1≤ 4 4

3≤ 4 3≤ 3≤ 8 8

1≤ 8 (Dowel)

9

1 ≤ 2

12 4

1 ≤

1 ≤ 16

1≤ 8

1≤ 8

1≤ 4 1≤ 8

1

1≤ 2

≤

1≤ 8

1 ≤ 16

1≤ 8

8

1≤ 2

1 ≤ 8 16

frame across it while keeping the frame in a vertical, upright position. 4. Finish sanding the faces and edges of the main-frame in the same way as in steps 1 to 3 using 150-grit sandpaper. 5. Turn down the corners and leading edges of the frame with a brief hand-application of the 60-grit paper, so as to avoid splinters.

Final Construction Procedure Once the front and rear sections of the sliding box-camera body have been built (see Chapter 2) and the fit of the main-frame has been verified against the slot in the rear section of the camera, the final procedure for constructing the wet-process film-holder may begin. For ease of comprehension, this has been divided into four subsections: installing the glass sheets and end-cap, making the dark16

Figure 1.7A, B, C, and D Four stages in making a filmholder joint. (A) Gluing two filmholder sections together in a 90° corner-clamp. (B) Drilling a 1/8≤ pilot hole. (C) Tapping a dowel into the hole with a mallet. (D) The finished joint with dowel ends protruding. A

B

C

D

Figure 1.8A, B, C, and D Finishing and sanding the mainframe of the film-holder. (A) Filling any gaps with putty. (B) Orbital-sanding the exterior faces. (C) Sanding the edges. (D) Turning down corners and leading edges. A

B

C

D

17

1 ≤ 4 1 ≤

8 16

3≤

Figure 1.9 The end-cap. 8≤ ¥ 10≤ wet-process film-holder. Front and side views.

slides, attaching light-traps to the main-frame, and painting the mainframe, dark-slides, and end-cap.

Installing the Glass Sheets and End-Cap Have a hardware store or frame shop cut you two 8≤ ¥ 10≤ sheets of single-strength, window-pane glass. These are to hold the negatives in place in the film-holder (see Chapter 4). Test fit the glass sheets by sliding them face-to-face in the 1/4≤ groove at the top of the main-frame of the film-holder. Once they are in place, up to about 1/16≤ of movement from side to side and front to back is acceptable, with the main-frame forming an approximate 1/4≤ border around the glass. Leaving the sheets of glass in place, slide the 3≤ ¥ 1/4≤ ¥ 81/16≤ piece of basswood in the 1/4≤ groove on top of the glass in order to form the end-cap (see Figure 1.9). The fit should be slightly on the loose side of snug, since the wood will expand slightly after being painted. Orbital-sand and edge-sand the wood with 60-grit sandpaper, followed by 150-grit sandpaper, as needed until an exact fit is achieved. Then turn down the corners and leading edges. When properly in place, the glass should be held securely and the end-cap should stick out about 1-1/4≤ from the top of the film-holder (see Figure 1.11).

Making the Dark-Slides Listed below are the procedural steps for making two dark-slides for the film-holder (see Figure 1.10): 1. Cut two 12-3/4≤ ¥ 8-1/16≤ sections of 1/8≤ thick Luan plywood using a straight-edge and utility knife. Make light passes with the utility knife, scoring the Luan until the board is cut, rather than trying to cut it completely at once. 2. Test fit the Luan sections cut in step 1 by sliding them into the 1/8≤ exterior slots of the main-frame of the filmholder. As the wood expands after painting, the fit should be slightly on the loose side of snug. Sand the surfaces and 18

9 ≤

8 16 1≤ 4

1≤ 8

1≤ 4

1≤ 8 1≤ 8

Figure 1.10 A dark-slide. 8≤ ¥ 10≤ wet-process film-holder. Front and side views.

1 ≤

3 ≤

11 4

12

3 ≤ 4

1≤ 2

1≤ 2

8 16

edges of the Luan with 60-grit and 150-grit sandpaper as needed. When completely in place, there should be about 1≤ of Luan sticking out from the top of the film-holder. 3. With a pencil, mark a line on both sides of the Luan sections, exactly where they stick out from the top of the main-frame. Double-check the lines by turning the faces around and switching slots on the main-frame, redrawing the lines each time (up to 1/16≤ of variance in the lines is acceptable). 4. Remove the Luan sections from the main-frame of the film-holder. 5. Taking two pieces of the 1/2≤ ¥ 1/8≤ ¥ 8-9/16≤ basswood frame-stock, glue them to the sides of one of the Luan sections so that they are running along the top of the drawn lines from step 3 and centered from left to right. Place a Cclamp at each end, and one in the middle, in order to hold 19

the pieces in position. Remove any excess glue with a scrap piece of frame-stock and allow to dry for a few hours. 6. Repeat step 5, gluing the remaining two pieces of 1/2≤ ¥ 1/8≤ ¥ 8-9/16≤ basswood frame-stock to the remaining Luan section.

Attaching Light-Traps to the Main-Frame Listed below are the procedural steps for attaching the light-traps to the film-holder main-frame, which can take place while the darkslides are gluing. (Note: if you are designing a film-holder for use with a modern 8≤ ¥ 10≤ view-camera, this section is to be omitted.) 1. Remove the end-cap and sheets of glass from the mainframe of the film-holder. 2. Install the main-frame into the slot at the rear of the sliding box-camera, marking a pencil-line on the sides and edges of the film-holder exactly where the main-frame sticks out from the camera. Double-check the lines by turning the film-holder around and redrawing the lines (up to 1/16≤ of variance in the line is acceptable). Remove the main-frame from the camera. 3. Glue the two 1/4≤ ¥ 1/4≤ ¥ 9-9/16≤ pieces of basswood frame-stock to the sides of the main-frame so that they are running along the top of the lines drawn in step 2, or as located in the diagram (see Figure 1.11). Place a C-clamp at each end and one in the middle to hold the pieces in position. 4. Glue the two 3/8≤ ¥ 1/4≤ ¥ 1≤ pieces of basswood framestock to the edges of the main-frame so that they are running along the top of the lines drawn in step 2, or as located in the diagram (see Figure 1.11). Adjust the C-clamps from step 3 as needed in order to hold the smaller pieces in place. Remove any excess glue with a scrap piece of frame-stock and allow the main-frame to dry for a few hours.

Painting the Main-Frame, Dark-Slides, and End-Cap Once the glue in the main-frame and dark-slides has dried, they are ready to be painted. The following steps bring the construction of the film-holder to completion: 1. Remove the C-clamps, brush off the pieces, and doublecheck the fit one last time, sanding as needed. 2. Apply a coat of flat-black enamel paint to the external surfaces of the main-frame, end-cap, and dark-slides using a 1≤-wide brush. Stir the paint thoroughly before use and WEAR PROTECTIVE GLOVES WHILE PAINTING IN A WELL-VENTILATED AREA. Clean the brush with turpentine after painting, followed by soap and water. 20

1≤

9 ≤

12

9 16

1≤

3≤ 10≤

11≤

11

1 ≤ 8

13

1 ≤ 2

1≤ 8

1≤ 4

1≤ 4

1≤ 4

3≤ 8

1≤ 4

1/ ≤ 4

1 ≤

8 16 1 ≤

9 16

3. After the first application of paint has dried, paint the inside grooves and top of the main-frame frame using a no. 5 brush. Don’t worry about the areas at the top of the main-frame that cannot be reached with the brush. Clean the brush immediately after use. 4. Once the paint has dried, double-check the fit, repainting any areas as needed. Upon drying, the film-holder is ready to be used.

Figure 1.11 The 8≤ ¥ 10≤ wetprocess film-holder. Complete with removable end-cap, glass, and darkslides in place. Front and side views.

Construction of the Focusing Screen Construction of the focusing screen is identical to that of the film-holder. The only difference is that the focusing screen has a sheet of glassine paper inserted between the sheets of glass, rather than the 21

3≤

94

1≤

82

1≤

62

4 14 ≤

Figure 1.12 The layout and marking of a 73/4≤ ¥ 9-3/4≤ sheet of glassine, for an 8≤ ¥ 10≤ focusing screen. Note that whole-plate, half-plate, and quarter-plate dimensions have been drawn on the glassine, and that the center has been indicated.

1≤

34

4 34 ≤ 6 12 ≤ 3≤

74

sensitized negatives and rubylith film. Ideally, the construction of the focusing screen should take place at the same time as the film-holder to save time and ensure that all dimensions are identical. Dark-slides are also recommended for the focusing screen to protect the glass in transport. Construction of a third, identical film-holder is also recommended if four negatives are to be sensitized and exposed at a time. (Note: if you are making a film-holder for a modern 8≤ ¥ 10≤ view-camera, you still need to make a focusing screen. The wetprocess film-holder places the negative in a slightly different position than the position for which the camera’s ground-glass is intended. You will also need to remove the normal ground-glass from the camera to use the focusing screen.) The marking and layout of the glassine is important since it allows for previsualization of a given scene (see Figure 1.12). The center of the format should also be indicated on the glassine since the primary focus of the lens will be located there (see Chapter 3). Any format smaller than the frame itself can be marked on the glassine as well, along with parallel-grid lines for architectural work or concentric circles for more critical examination of the circle of definition. Given the 8≤ ¥ 10≤ film-holder described above, the steps of marking and layout of a sheet of glassine for an intended whole-plate dimension measuring 6-1/2≤ ¥ 8-1/2≤ are as follows: 22

1. With a straight-edge and utility knife, cut the glassine to 73/4≤ ¥ 9-3/4≤. 2. With a black magic marker and straight-edge, draw the 61/2≤ ¥ 8-1/2≤ format on the glassine, taking care to center the format exactly. It is also a good idea to draw the halfplate and quarter-plate dimensions. Indicate the center of the rectangle by marking off the diagonals as well. 3. Making sure that the two pieces of 8≤ ¥ 10≤ glass are clean and dry, position the piece of glassine onto one of them so that it is exactly centered with a 1/8≤ border of glass all around. Using 1/2≤-wide cellophane tape, tape the glassine into position. Trim off any tape that exceeds the margins of the glass. 4. Place the second sheet of glass on top of the first, with the glassine sandwiched in between. 5. Slide the glass sheets into the main-frame of the filmholder and slide the end-cap on top of the glass. The focusing screen is now ready to be used.

Using the Focusing Screen and Film-Holder Use of the focusing screen and film-holder assumes that the camera and lens have been built, and that paper negatives have been sensitized (see Chapters 2 to 4). Once these conditions have been met, the photographic subject or view should be chosen, and the camera and tripod set up. With camera firmly secured, slide the focusing screen into the slot at the rear of the camera and remove the darkslides. Draping a dark-cloth (2 square yards of black velvet folded in half) over your head and the back of the camera to screen out extraneous light, adjust the focus until the inverted image received on the glassine is in focus. Reposition and refocus as needed, using an 8¥ loupe to check the focus of specific details. Once the view and focus have been determined to your satisfaction, replace the dark-slides and remove the focusing screen, taking care not to disturb the positioning of the camera. Slide the film-holder into the slot at the rear of the camera, making sure that the proper negative is facing the lens and again taking care not to disturb the positioning of the camera. Place the lens-cap over the lens (see Chapter 3) and remove the dark-slide facing the lens. Rest the dark-slide on top of the film-holder so as to prevent light from coming in from the top. Turning the dark-slide upside-down and sliding the very short end at the top into the film-holder also works. The lens-cap is then removed from the lens, and the exposure is made. Replace the lens-cap and the dark-slide, remove the film-holder, and you are ready to move on to the next picture or to process the exposed negative. Note: since the film-holder and focusing screen are identical, it is a good idea to include an identifying mark of some sort to distinguish one from the other and not accidentally expose the negatives. To prevent this from happening, I use a silver marking pen, labeling 23

the top of the main-frame of the focusing screen with the words “Focusing Screen.” The top of the dark-slides of the film-holder should also be marked so as to indicate whether a given side of the film-holder has been exposed. Here I write “Unexposed” along a light-trap on one side of a dark-slide and “Exposed” on the other side. Upon loading the sensitized negatives into the main-frame, the “Unexposed” sides of the dark-slides are oriented to face outwards, and, following exposure, the “Exposed” sides are turned to face outwards. In this way, accidental double-exposure of the same side of the film-holder is avoided. Marking the faces of the film-holder “A” and “B” also helps, particularly if more than one film-holder is to be used, the faces of the second film-holder becoming “C” and “D,” and so forth (see Figure 1.13).

THE DRY, WAXED-PAPER FILM-HOLDER Figure 1.13 An 8≤ ¥ 10≤ wetprocess film-holder after a year of wear and tear. Note that an “A-side” and “B-side” are indicated on the main-frame of the film-holder, along with the “shot” and “unshot” sides of the dark-slides. This is to prevent accidental double-exposure of the negative.

The 10≤ ¥ 12≤ film-holder described below is intended for use with dry, waxed-paper process negatives, trimmed down to a final dimension of 210 mm ¥ 270 mm. This film-holder is essentially a modification of the film-holder given for the wet-paper process, chief differences being the substitution of a Luan section for the glass in the middle of the frame and the size and thickness of the film-holder frame. This film-holder has not been designed with any direct source in mind, although I used a few suggestions gleaned from Arsène Pélegry’s account of his dry-paper process.22 The film-holder design given here may be modified for use with larger or smaller format cameras. All that you need to do is adjust the basswood lengths and Luan dimensions as specified, to match any given format size and lens focal length combination (see Chapters 2 and 3 for more on this subject). Otherwise, the dimensions and procedural steps should remain nearly the same. Note: with careful measurement, both the film-holder and camera body can be built separately. Nevertheless, it is recommended that the construction of the film-holder and camera occur in tandem with each other (see Chapter 2). This is to ensure accuracy of fit with regard to the sanding of the film-holder and camera body, and the placement of the light-traps on the film-holder. The construction procedures given below have been divided into two major sections. The first section, or initial construction procedure, pertains to the main-frame of the film-holder and ideally occurs in tandem with the construction of the frame and exterior faces of the foldingcamera. Once the fit of both component parts has been verified, the second section, or final construction procedure, may proceed independently.

Initial Construction Procedure The initial procedure for constructing the dry, waxed-paper filmholder is given below. For ease of comprehension, this has been 24

divided into five subsections: cutting wood to size, constructing the bottom section, constructing the side sections, assembling the mainframe, and finishing and sanding the main-frame.

Cutting Wood to Size The width and thickness dimensions of basswood frame-stock are previously cut by the manufacturer and sold in the form of 2¢ and 3¢ lengths. In this way, two or more specified lengths may be obtained from an original 2¢ or 3¢ length. Cut the basswood frame-stock to the following specified lengths using a modeler’s razor saw and miter box:

• • • • • • • • • •

Four 3/4≤ ¥ 1/8≤ ¥ 13-1/16≤ Eight 3/4≤ ¥ 1/8≤ ¥ 9-1/2≤ Two 1/2≤ ¥ 1/8≤ ¥ 12-1/16≤ Four 1/2≤ ¥ 1/8≤ ¥ 12-9/16≤ Four 1/2≤ ¥ 1/8≤ ¥ 12-1/4≤ One 1/2≤ ¥ 5/32≤ ¥ 12-1/16≤ Two 1/2≤ ¥ 5/32≤ ¥ 12-1/4≤ Two 1/4≤ ¥ 1/4≤ ¥ 13-9/16≤ Two 3/8≤ ¥ 1/4≤ ¥ 29/32≤ Four 2≤ ¥ 1/8≤ ¥ 13-1/16≤ (Note: wood that is wider than the miter box may still be cut with it. First mark the line to be cut in pencil, then lean the wood into the miter box so that the saw can line up with one of the slots in the miter box and the line marked on the wood.) • One 3≤ ¥ 5/32≤ ¥ 12-1/16≤ The diameters of basswood dowels are also determined by the manufacturer and sold in the form of 3¢ and 4¢ lengths. As very little dowel material will be used in the construction of the film-holder, one 3¢ length of a 1/8≤ dowel will be sufficient. Cut the dowel with a utility knife, rather than a saw, to avoid tearing the ends of the dowel. Mark a line on the length of the dowel where the intended cut is to be made, and then roll the dowel beneath the razor’s edge at the indicated mark, gradually increasing the pressure of the utility knife until the cut is made. Using this suggested cutting method, cut the following basswood dowel sections:

• Six 1/8≤ ¥ 1-1/32≤ Constructing the Bottom Section Taking the four 3/4≤ ¥ 1/8≤ ¥ 13-1/16≤ pieces, the two 1/2≤ ¥ 1/8≤ ¥ 12-1/16≤ pieces, and the individual 1/2≤ ¥ 5/32≤ ¥ 121/16≤ piece, start to make the bottom section of the film-holder, gluing the basswood pieces together according to the indicated diagram (see Figure 1.14). Spread the glue out evenly, making sure that the pieces are centered and flush with regard to what will be the 25

1 " 1 " 1 " 8 8 8 5 " 32 1 " 1 " 8 1 " 8 8

1

1 " 2

3 " 4

13 16 "

1

1 " 2

12 16 "

1 " 2

Figure 1.14 Bottom section. 10≤ ¥ 12≤ dry, waxed-paper filmholder. Top and front views.

bottom edge of the film-holder. Use three C-clamps to hold the pieces of wood in place, one placed in the middle and the other two at each end (see Figure 1.4). Remove any excess glue before it dries completely by sliding scrap pieces of frame-stock into the grooves and along the edges. Allow to dry for a few hours with the C-clamps in place.

Constructing the Side Sections Taking four 3/4≤ ¥ 1/8≤ ¥ 9-1/2≤ pieces, two 1/2≤ ¥ 1/8≤ ¥ 12-1/4≤ pieces and one 1/2≤ ¥ 5/32≤ ¥ 12-1/4≤ piece, start to make one of the side sections of the film-holder by gluing the basswood together according to the indicated diagram (see Figure 1.15). Spread the glue out evenly, making sure that the pieces are in the right location and flush with regard to what will be the side edge of the filmholder. Use three C-clamps to hold the pieces of wood in place, one placed in the middle and the other two at each end (see Figure 1.4). Remove any excess glue before it dries completely by sliding scrap pieces of frame-stock into the grooves and along the edges. Allow to dry for a few hours with the C-clamps in place. Make the other side section in exactly the same way using the remaining four 3/4≤ ¥ 1/8≤ ¥ 9-1/2≤ pieces, the remaining two 1/2≤ ¥ 1/8≤ ¥ 12-1/4≤ pieces, and the remaining 1/2≤ ¥ 5/32≤ ¥ 12-1/4≤ piece. Both side sections are identical.

Assembling the Main-Frame Once the bottom and side sections have dried, remove the Cclamps and trim away any excess glue with a utility knife. Check the fit of the three sections by putting them together according to the diagram along with the four 2≤ ¥ 1/8≤ ¥ 13-1/16≤ pieces that form the top of the main-frame (see Figure 1.16). Everything should fit closely, with only small gaps or protrusions (up to 1/16≤ is acceptable). Once the fit has been verified, take the sections apart and proceed to assemble the main-frame as follows (see Figure 1.7): 26

Finishing and Sanding the Main-Frame Once the glue in the main-frame has dried, the following steps bring the assembly of the main-frame to completion (see Figure 1.8):

3 " 4

12

9

1 " 4

1 " 2

2"

1 " 1 " 1 " 8 8 8 5 " 32 1 " 8 1 " 1 " 8 8

1. Line the exposed, bottom area of one of the side sections with glue. Fit this to the corresponding area of the bottom section and place the two joined sections into a 90° cornerclamp. Tighten the clamp until both sections are firmly held, double-checking to make sure that the angle formed is square. 2. While the sections are gluing, drill a 1/8≤ pilot hole in the area where the two sections overlap and join, as indicated in the diagram (see Figure 1.16). 3. Add a drop of glue to the drilled hole from step 2, followed by lining one of the 1/8≤ ¥ 1-1/32≤ dowels with a small amount of glue as well. Taking a mallet, lightly tap the dowel into the hole (if you use a hammer, place a block of wood in between the hammer and the dowel to soften the blow). When the dowel is completely in the joint, approximately 1/16≤ of the dowel should stick out on both sides of the main-frame. This will be sanded later. 4. Remove the wood from the corner-clamp and repeat steps 1 to 3, attaching the other side section to the bottom section in exactly the same way. Remove the wood from the corner-clamp and wipe off the excess glue from both joints. 5. Taking the four 2≤ ¥ 1/8≤ ¥ 13-1/16≤ pieces, glue them into place at the top of one of the side sections, again using the 90° corner-clamp. Once the pieces are lined up with one side section, and the clamp is holding everything secure, drill two 1/8≤ pilot holes where the top pieces overlap the side section, as indicated in the diagram (see Figure 1.16). 6. Repeat step 3, installing a dowel into each of the drilled holes. Once the dowels are in place, remove the wood from the corner-clamp. 7. Repeat steps 5 and 6, joining the top pieces to the other side section. Remove the wood from the corner-clamp and allow the main-frame assembly to dry for a few hours.

1 " 1" 2 4 3" 4

Figure 1.15 Side section. 10≤ ¥ 12≤ dry, waxed-paper filmholder. Side and front views.

1. Fill any gaps on the exterior of the main-frame with putty using a putty knife. Allow to dry. 2. With an orbital hand-sander, sand the two exterior faces of the main-frame using 60-grit sandpaper. Follow the grain of the wood, sanding until the faces are even and the dowel ends are flush. ALWAYS WEAR SAFETY GLASSES AND A DUST MASK WHEN SANDING. ALWAYS SAND IN AN AREA WHERE THERE IS ADEQUATE VENTILATION. 27

1 ≤

13 16

(Dowel)

1≤ 8

1≤ 1≤ 2

1≤ 2

1≤

2≤

1≤ 2

1≤ 8 (Dowel)

29≤ 32

1≤ 2

1≤ 1≤ 4 4

Figure 1.16 Initial assembly of the main-frame. 10≤ ¥ 12≤ dry, waxedpaper film-holder. Front and side views.

1≤ 5 ≤ 8 1≤ 1 ≤ 32 8 8

1≤

1≤ 2

1 ≤ 16

1≤ 8

8

1≤ 2

1 ≤ 12 16

1≤8

3≤ 3≤ 8 8

3≤ 4 3≤ 3≤ 8 8

1≤ (Dowel) 8

92

1≤

12

1 ≤ 4

1 ≤ 16

3. Sand the side, bottom, and top edges of the main-frame until they are even and square. Edge sanding is most easily achieved by taping a sheet of 60-grit sandpaper to a worktable or hard surface, and then passing the edges of the frame across it while keeping the frame in a vertical, upright position. 4. Finish sanding the faces and edges of the main-frame in the same way as in steps 1 to 3 using 150-grit sandpaper. 5. Turn down the corners and leading edges of the frame with a brief hand-application of the 60-grit paper so as to avoid splinters.

Final Construction Procedure Once the fit of the main-frame has been verified against the frame and exterior faces of the folding-camera (see Chapter 2), the 28

5≤ 32

Figure 1.17 The end-cap. 10≤ ¥ 12≤ dry, waxed-paper filmholder. Front and side views.

3≤

1≤ 12 16

final procedure for constructing the film-holder may proceed. For ease of comprehension, this has been divided into four subsections: installing the Luan divider and end-cap, making the dark-slides, attaching light-traps to the main-frame, and painting the main-frame, dark-slides, Luan divider, and end-cap.

Installing the Luan Divider and End-Cap With a straight-edge and utility knife, cut a 10≤ ¥ 12≤ section of 1/8≤-thick Luan plywood. Make light passes with the utility knife, scoring the Luan until the board is cut, rather than trying to cut it completely at once. This is to serve as the central barrier between the negatives (see Chapter 4). Test fit the Luan divider, sliding it in the 5/32≤ groove at the top of the main-frame of the film-holder. Once they are in place, up to about 1/16≤ of movement from side to side and front to back is acceptable, with the main-frame forming an approximate 1/4≤ border around the divider. Sand the faces and edges of the divider as needed. Leaving the Luan divider in place, slide the 3≤ ¥ 5/32≤ ¥ 121/16≤ piece of basswood in the 5/32≤ groove, on top of the Luan divider, to form the end-cap (see Figure 1.17). The fit should be slightly on the loose side of snug, since the wood will expand slightly after being painted. Orbital-sand and edge-sand the wood with 60grit sandpaper, followed by 150-grit sandpaper, as needed, until an exact fit is achieved. Then turn down the corners and leading edges. When completely in place, the Luan divider should be held securely and the end-cap should stick out about 1-1/4≤ from the top of the film-holder (see Figure 1.19).

Making the Dark-Slides Listed below are the procedural steps for making two dark-slides for the film-holder (see Figure 1.18): 1. Cut two 12-3/4≤ ¥ 12-1/16≤ sections of 1/8≤-thick, Luan plywood using a straight-edge and utility knife. 2. Test fit the Luan sections cut in step 1 by sliding them into the 1/8≤ exterior slots of the main-frame. As the wood expands after painting, the fit should be slightly on the 29

1" 1" 1" 8 8 8

9

12 16 " 1

12 16 "

1" 4

3 " 4

11

12 4

3 "

1 " 2

1 " 2

1" 4

Figure 1.18 A dark-slide. 10≤ ¥ 12≤ dry, waxed-paper filmholder. Front and side views.

loose side of snug. Sand the surfaces and edges of the Luan with 60-grit and 150-grit sandpaper, as needed. When completely in place, there should be about 1≤ of Luan sticking out from the top of the film-holder. 3. With a pencil, mark a line on both sides of the Luan sections, exactly where they stick out from the top of the main-frame. Double-check the lines by turning the faces around and switching slots on the main-frame, redrawing the lines each time (up to 1/16≤ of variance in the lines is acceptable). 4. Remove the Luan sections from the main-frame of the film-holder. 5. Taking two pieces of the 1/2≤ ¥ 1/8≤ ¥ 12-9/16≤ basswood frame-stock, glue them to the sides of one of the Luan sections, so that they are running along the top of the drawn lines from step 3 and centered from left to right. Place a C-clamp at each end and one in the 30

13 "

1 32

29 " 32

9

13 16 " 1" 4

1" 4

3"

1" 4

1 " 4

10 "

11 "

1 "

11 8

13 2

1 "

1" 8

3 " 8

1

12 16 " 1

13 16 "

middle to hold the pieces in position. Remove any excess glue with a scrap piece of frame-stock and allow to dry for a few hours. 6. Repeat step 5, gluing the remaining two pieces of 1/2≤ ¥ 1/8≤ ¥ 12-9/16≤ basswood frame-stock to the remaining Luan section.

Figure 1.19 The 10≤ ¥ 12≤ dry, waxed-paper film-holder. Complete with removable end-cap, Luan divider, and dark-slides in place. Front and side views.

Attaching Light-Traps to the Main-Frame Listed below are the procedural steps for attaching the lighttraps to the film-holder main-frame, which can take place while the dark-slides are gluing. 31

1. Remove the end-cap and Luan divider from the mainframe of the film-holder. 2. Install the main-frame into the slot at the rear of the folding-camera, marking a pencil-line on the sides and edges of the film-holder exactly where the main-frame sticks out from the camera. Double-check the lines, by turning the film-holder around and redrawing the lines (up to 1/16≤ of variance in the line is acceptable). Remove the main-frame from the camera. 3. Glue the two 1/4≤ ¥ 1/4≤ ¥ 13-9/16≤ pieces of basswood frame-stock to the sides of the main-frame so that they are running along the top of the lines drawn in step 2, or as located in the diagram (see Figure 1.19). Place a C-clamp at each end and one in the middle to hold the pieces in position. 4. Glue the two 3/8≤ ¥ 1/4≤ ¥ 29/32≤ pieces of basswood frame-stock to the edges of the main-frame so that they are running along the top of the lines drawn in step 2, or as located in the diagram (see Figure 1.19). Adjust the Cclamps from step 3 as needed, in order to hold the smaller pieces in place. Remove any excess glue with a scrap piece of frame-stock and allow the main-frame to dry for a few hours.

Painting the Main-Frame, Dark-Slides, Luan Divider, and End-Cap Once the glue in the main-frame and dark-slides has dried, the sections are ready to be painted. The following steps bring the construction of the film-holder to completion: 1. Remove the C-clamps, brush off the pieces, and doublecheck the fit one last time, sanding as needed. 2. Apply a coat of flat-black enamel paint to the external surfaces of the main-frame, end-cap, and dark-slides using a 1≤-wide brush. Stir the paint thoroughly before use and WEAR PROTECTIVE GLOVES WHILE PAINTING IN A WELL-VENTILATED AREA. Clean the brush with turpentine after painting, followed by soap and water. 3. After the first application of paint has dried, paint the inside grooves and top of the main-frame using a no. 5 brush. Don’t worry about the areas at the top of the mainframe that cannot be reached with the brush. Clean the brush after use. 4. Once the paint has dried, double-check the fit, repainting any areas as needed. Upon drying, the film-holder is ready to be used (see Figure 1.20).

32

Figure 1.20 A recently finished 10≤ ¥ 12≤ dry, waxed-paper film-holder ready for use. Note that an “A-side” and “B-side” are indicated on the main-frame of the film-holder, along with the “shot” and “unshot” sides of the dark-slides. This is to prevent accidental double-exposure of the negative.

Construction of the Focusing Screen The focusing screen for the dry, waxed-paper negatives is identical to the film-holder except for the substitution of a 10≤ ¥ 12≤ sheet of single-strength, window-pane glass for the Luan divider in the main-frame. Have a hardware store or frame shop cut the glass for you. Prior to installing the glass, mark out the dimension of the format you intend to use (for example, 210 mm ¥ 270 mm) on a 93/4≤ ¥ 11-3/4≤ sheet of glassine, following the example given for the wet-paper process film-holder (see Figure 1.12). Tape all of the edges of the glassine onto glass. Since there will not be a second sheet of glass to hold the paper flat, you should make sure that the glassine is taut before taping it down. An alternative is to use dried skim milk instead of glassine, a method for achieving this being given below, under the “ground-glass substitutes” heading.

Using the Film-Holder and Focusing Screen Use of the dry, waxed paper film-holder and focusing screen is the same as the wet-process film-holder and focusing screen, with two exceptions. The first is that the dry, waxed-paper negatives should be taped by their edges onto the Luan divider after it has been loaded in the main-frame. Taping is done to prevent any curling of the paper from interfering with the dark-slides’ passage into the main-frame upon loading, with the tape being removed from the negative prior to processing. The second is that in focusing the image, you should make sure that the glassine in the focusing screen is always oriented towards the lens. Turning the glassine away from the lens will result in a 1/8≤ discrepancy between the focusing screen and the filmholder. To avoid this, indicate the side of the focusing screen with the glassine, marking the corresponding side of the main-frame with a

33

silver marking pen. Other identifying marks should resemble those given under the construction of the wet-process film-holder.

GROUND-GLASS SUBSTITUTES Glassine has been given as a substitute for ground-glass in the construction of both focusing screens described in this chapter. This is because glassine is cheap and easy to use, whereas ground-glass is expensive and difficult to make. And while the image received on glassine is not quite as fine as that received on ground-glass, it still allows one to focus critically and effectively. I have tried using tracing paper and Mylar of varying opacity and thickness instead of glassine, only to find glassine to be the best substitute. At some point, however, particularly with the dry, waxed-paper film-holder, you may want to make a focusing screen that does not require a separate sheet of paper. One alternative, suggested by Sir David Brewster, uses skim milk and is made in the following way:23 1. In a dust-free place, level the sheet of glass intended to be used as the focusing screen. 2. Pour just enough skim milk (1 percent milk-fat) to cover the sheet of glass, removing air-bubbles and spreading the milk out with a 1≤-wide strip of paper. 3. Allow the milk to evaporate for 1 or 2 days. When dry, the surface should be shiny and somewhat irregular. This irregularity should not be too apparent when viewed by transmitted light. 4. Spray the dried surface with a matte spray fixative to prevent the milk surface from deteriorating. Apply the spray as soon as the milk is completely dry, since further delay results in the milk cracking and eventually flaking off the glass. 5. Once the protective spray has dried, scrape off any residual dried milk on the other side of the glass with a razor blade. Mark off the format (for example, 210 mm ¥ 270 mm) with a magic marker—on the backside of the glass rather than the dried milk surface—and the glass sheet is ready for use.

NOTES 1. A study of Talbot’s pioneering efforts in photography can be found in Larry Schaaf ’s Out of the Shadows: Herschel, Talbot and the Invention of Photography (New Haven [CT]: Yale University Press, 1992). 2. For an example of Talbot’s unawareness of the rules of perspective theory, see Schaaf, Out of the Shadows, 73, fig. 41. 3. For an appreciation of Talbot’s evolution as a photographic artist, see Larry Schaaf, The Photographic Art of William Henry Fox Talbot (Princeton [NJ]: Princeton University Press, 2000).

34

4. For an early French account of Talbot’s process, see N[öel]-P[aymal] Lerebours, Traité de photographie, 4th ed. (Paris: Lerebours, 1843), 146–50. For details of Guillot-Saguez’s process, see [A.] GuillotSaguez, Méthode théorique et pratique de photographie sur papier (Paris: Victor Masson, 1847). For details of Blanquart-Évrard’s process, see LouisDésiré Blanquart-Évrard, Procédés employés pour obtenir les épreuves de photographie sur papier (Paris: C. Chevalier, 1847). For details of Le Gray’s dry, waxed-paper process, see Gustave Le Gray, Nouveau traité théorique et pratique de photographie sur papier et sur verre (Paris: Lerebours et Secretan, 1851). 5. For early daguerrean equipment and format standards, see Lerebours, Traité de photographie; and Charles Chevalier, Mélanges photographiques (Paris: [self-published], 1844). 6. Guillot-Saguez, Méthode théorique, 11. 7. Ibid., 12. 8. What little is known about Guillot-Saguez is discussed in André Jammes and Eugenia Parry Janis, The Art of French Calotype (Princeton [NJ]: Princeton University Press, 1983), 185–87. 9. Le Gray, Nouveau traité théorique, 80. 10. Ibid. 11. For a catalogue of the photographic work of Henri Le Secq, see Eugenia Parry Janis and Josiane Sartre, Henri Le Secq, photographe de 1850 à 1860 (Paris: Musée des Arts Décoratifs, 1986). 12. A circa 1845 advertisement for Claudet’s studio is reproduced in Rollin Buckman, The Photographic Art of Calvert Richard Jones (London: Science Museum, 1990), 6, fig. 5. 13. For more on the work of Hill and Adamson, see David Bruce, Sun Pictures: The Hill-Adamson Calotypes (Greenwich [CT]: New York Graphic Society, 1973). 14. For more on John Muir Wood, see Sara Stevenson, Julie Lawson, and Michael Gray, The Photography of John Muir Wood 1805–1892, An Accomplished Amateur ([n.p.]: Scottish National Portrait Gallery, 1988). 15. See Horne and [W.H.] Thornthwaite, Horne & Thornthwaite’s Descriptive Catalogue of Scientific Instruments, 4th ed. (London: [self-published], 1855), pt. 2, 89–120. I am indebted to Roger Taylor for bringing this catalogue to my attention. 16. Thomas Sutton, The Calotype Process: A Hand Book to Photography on Paper, (London: Joseph Cundall, 1855), 32. 17. For a thorough attempt to systematize the calotype process, citing much of the accumulated knowledge of his day, see D[ésiré] v[an] Monckhoven, Méthodes simplifiées de photographie sur papier (Paris: Marion, 1857). 18. Ibid., 119. The quoted passage referring to 18 cm ¥ 23 cm was actually published as 18 cm ¥ 32 cm, an apparent typo given the preceding and subsequent remarks. 19. D[ésiré] v[an] Monckhoven, Traité général de photographie, 3rd ed. (Paris: Victor Masson, 1863), 139. 20. Ibid., 178. 21. Thomas’ alleged account of Flacheron’s process is to be found in Robert Hunt, A Manual of Photography, (1853; reprint, New York: Arno, 1973), 233–36. 22. Pélegry’s modification of the dry-waxed paper process is given in Arsène Pélegry, La Photographie: des peintres, des voyageurs et des touristes

35

(Paris: Gauthier-Villars, 1885); and A[lphonse] Davanne, La Photographie: traité théorique et pratique (Paris: Gauthier-Villars, 1888), v.1, 451–57. 23. For more on making a focusing screen with skimmed milk, see David Brewster, A Treatise on Optics, rev. ed. (London: Longman, Brown, Green, and Longmans, 1853), 461.

36

2 The Camera Body This chapter addresses the construction of two types of camera, both adapted from sources dating to the mid-1850s. The first camera is a sliding box-camera. Focusing is achieved by moving either the front or back of the camera with the lens remaining in a fixed position. It may be used with wet-paper process or dry, waxed-paper negatives, as well as with symmetrical, asymmetrical, and landscape lenses (see Chapters 3 and 4). Depending on the lens used and how much negative material is eventually trimmed away, it allows for images ranging from 3-1/4≤ ¥ 4-1/4≤ to 8≤ ¥ 10≤ (see Chapter 1 for more on negative formats). The second camera is a folding-camera. Focusing is achieved by moving the lens barrel back and forth with the camera body remaining in a fixed position. The camera’s collapsibility, combined with its more limited focusing range, makes it more practical as a portable travel camera, using dry, waxed-paper negatives in combination with a landscape lens. Depending on how much negative material is trimmed away, negative size varies from 8≤ ¥ 10≤ to 10≤ ¥ 12≤.1 The camera body is perhaps the simplest apparatus needed for photography. Its primary function is to hold the lens at an appropriate distance from the film plane so that light may be focused upon it. Its secondary function is to prevent extraneous light from entering between the lens and the film plane during the exposure of the negative, and while focusing and composing the image. In its simplest form, it is little more than a darkened room, or camera obscura, in which light is made to enter through a small hole, resulting in an inverted image being projected upon a screen or wall opposite the hole. Reduced to the scale of a box, this is the principle underlying pinhole photography.2 The first recorded placement of a lens in the hole of a camera obscura dates to the first half of the sixteenth century and is attributed to Girolamo Cardano. Giovanni Battista della Porta is often said to have been its originator due to his description of using a lens in combination with a viewing screen in a popular mid- to late sixteenth-century treatise. From these rather static approaches 37

to optical projection, smaller, portable-box-camera obscura designs evolved in the seventeenth century, where they were put to notable use by artists like Vermeer and Canaletto the elder. In particular, portable camera obscura designs published by Johann Zahn in 1685–86 bear striking similarities to the first cameras used by photographers (see Figure 2.1).3 Folding camera obscura designs were first introduced in the mideighteenth century, many of them being quite ingenious. For instance, a number of folding camera obscura designs surviving from this era were designed to unfold from the casings of large, leather-bound books. During use, the cover of the book opened in order to unfold the working apparatus of the camera. After use, the camera was folded back into the casing, whereupon it passed as a large book.4 By the late eighteenth century, smaller folding designs were in vogue. One in particular, designed by an English optician known only as Professor Clover, was approximately 3-1/2≤ ¥ 4≤ ¥ 10≤ when in use. Folded up, it resembled a Polaroid SX-70.5 The first recorded attempt of using a camera obscura for photographic purposes dates to a scientific journal from 1802, wherein Sir Humphry Davy described the earlier researches of his friend Thomas Wedgwood.6 The exact dimensions of Wedgwood’s

Figure 2.1 Late seventeenth century portable camera obscura designs by Johann Zahn. Detail from an illustration in Johann Zahn, Oculo Artificiali Teledioptrico (Herbipoli [Wurzburg], 1686), v. 3, opposite 219, plate 22. Reproduced by permission of the Houghton Library, Harvard University.

38

camera are not known, but it was no doubt similar to one of many portable camera obscura designs available in the late eighteenth to early nineteenth century. The earliest surviving photograph from nature, taken by Nicéphore Niépce in 1827, was also made using a portable camera obscura modified for photographic purposes. It measured 305 mm high, 315 mm wide, and 370 mm long when closed. The lens focal length was approximately 385 mm, for a format measuring approximately 160 mm ¥ 190 mm. Focusing was achieved by sliding the rearmost of two interlocking boxes. In essence, it differed very little from the sliding box-camera presented below.7 The first folding-camera for photographic use was Charles Chevalier’s Grand Photographe, which dates to 1840. This was a large, daguerrean studio camera with hinges on the side, allowing it to be collapsed when not in use. Focus was achieved by a sliding camera back, with a reflecting prism being added to the front of the lens to correct the inherent lateral reversal of the daguerreotype image (see Figure 2.2).8

Figure 2.2 Chevalier’s Grand Photographe. Detail from a folding plate at the end of Charles Chevalier, Nouvelles instructions sur l’usage du daguerréotype (Paris, 1841). Reproduced by permission of the Department of Printing and Graphic Arts, Houghton Library, Harvard College Library.

39

TOOLS NEEDED Many of the tools needed to make cameras are the same as those needed to make film-holders (see Chapter 1). In addition to these, you will need the following items, which can be obtained from most hardware stores:

• • • • • • • • • • • • •

A hammer A nail set Wire cutters Two hog-hair or synthetic-bristle brushes, 1/2≤ wide and 2-1/2≤–3≤ wide A caulk gun A flathead screwdriver A 3/16≤ drill-bit A 3/8≤ drill-bit A hand-saw A 3/4≤ wood chisel A pair of scissors A torpedo level A focusing loupe (the inexpensive, 8¥ plastic variety is fine)

MATERIALS NEEDED Many of the materials needed to make cameras are also the same as those needed to make film-holders. In addition to these, you will need the following materials, which can be obtained from most hardware and art-supply stores:

• • • • • • • • • • • •

40

1≤ finish nails 1/2≤ wire nails Black, vinyl adhesive caulk (Phenoseal“ is recommended) A half-pint of polyurethane varnish A number of 2¢ or 3¢ lengths of 1/2≤ ¥ 1/2≤ basswood frame-stock (final lengths are cut to the dimensions specified in the procedural steps) A number of 2¢ or 3¢ lengths of 1≤ ¥ 1/2≤ basswood framestock (final lengths are cut to the dimensions specified in the procedural steps) One to four brass 1/4-20 bushings, 1/2≤ length 3/8≤ outerdiameter Four 1≤ aluminum screw-posts One 2¢ length of 1 ¥ 4 pine (actual dimension is 2¢ ¥ 3/4≤ ¥ 3-1/2≤) Two wooden yardsticks with millimeter markings 2 square yards of black velvet (for a dark-cloth) 2 yards of 2≤-wide, black cloth ribbon, or 1 square yard of book-cloth

THE SLIDING BOX-CAMERA The 8≤ ¥ 10≤ sliding box-camera, as constructed according to the procedural steps given below, is intended for use with the wetpaper process film-holder and focusing screen (see Chapter 1). It takes a 5≤ ¥ 5≤ lens board, allowing for lenses of different configurations and focal lengths to be easily installed and removed (see Chapter 3). Front camera movements allow for a rising action of the lens when the camera is in a vertically oriented position, and a sideto-side shifting action when the camera is in a horizontally oriented position. Focus is achieved by sliding either the front or back of the camera until a focused image is received upon the focusing screen. Fully closed, the distance between the film plane and the lens board measures approximately 10≤ (255 mm). Fully extended, this distance measures approximately 16≤ (410 mm). Depending on where the lens barrel and optical elements are located, the camera has a minimum focal length of about 225 mm for quarter-plate and halfplate formats, and a maximum focal length of about 15≤ for wholeplate and 8≤ ¥ 10≤ formats (see Chapters 1 and 3). The camera is used in combination with a platform base, which serves to connect the camera to a tripod and aids in supporting the camera while focusing. This camera has not been designed with a direct source in mind. Like the film-holders, it is mostly the result of trial and error. Starting from some general indications given in mid-1850s technical manuals (see Figure 2.3),9 I eventually arrived at my own configuration. Otherwise, the design has mostly been influenced by a desire to keep things simple and inexpensive. Design specifications, as given below, may be modified for use with larger or smaller format film-holders. All that you need to do is adjust the basswood lengths and Luan dimensions given here, in order to match a different format size and lens focal length combination (see Chapters 1 and 3). Otherwise, the construction procedures remain largely the same. With careful measurement, both the sliding box-camera and wet-process film-holder can be built separately. Nevertheless, it is recommended that the construction of the camera occur in tandem with the construction of the film-holder (see Chapter 1). This is to ensure accuracy of fit with regard to the sanding of the film-holder and camera body, and the placement of the light-traps on the filmholder. The construction procedures given below have been divided into two major sections. The first section, or initial construction procedure, pertains to the assembly of the front and rear sections of the camera body. This should occur in tandem with the initial construction of the main-frame of the film-holder. Once the fit of both parts has been verified, the second section, or final construction procedure, may proceed. This also includes the assembly of the camera platform.

41

Figure 2.3A and B Two midnineteenth century sliding boxcameras. (A) Reprinted from W. [Marcus] Sparling, Theory and Practice of the Photographic Art (1853; reprint, New York, 1973), 40, fig. 37. (B) Reprinted from W. [Marcus]Sparling, Theory and Practice of the Photographic Art (1853; reprint, New York, 1973), 41, fig. 40.

A

B

Initial Construction Procedure: Camera Body The initial procedure for constructing the front and rear sections of the camera body is given below. For ease of comprehension, this has been divided into four subsections: cutting basswood frame-stock to size, construction of the rear and front section frames, cutting the Luan, and attaching the Luan sides and focusing rails.

Cutting Basswood Frame-Stock to Size The width and thickness dimensions of basswood frame-stock are previously cut by the manufacturer and sold in the form of 2¢ and 3¢ lengths. In this way, two or more specified lengths may be obtained from an original 2¢ or 3¢ length. Cut the basswood frame-stock to the following number of specified lengths using a modeler’s razor saw and miter box:

• Two 1/4≤ ¥ 1/2≤ ¥ 8-1/16≤ • Eight 1/2≤ ¥ 1/2≤ ¥ 6≤ • Eight 1/2≤ ¥ 1/2≤ ¥ 8-1/16≤ 42

• • • • • • • • • •

Twelve 1/2≤ ¥ 1/2≤ ¥ 10-1/2≤ Ten 1/2≤ ¥ 1/2≤ ¥ 5-1/2≤ Four 1/2≤ ¥ 1/2≤ ¥ 8≤ Four 1/2≤ ¥ 1/2≤ ¥ 10-7/16≤ Two 1/2≤ ¥ 1/2≤ ¥ 9-5/16≤ Two 1/2≤ ¥ 1/2≤ ¥ 24≤ Four 1/2≤ ¥ 1/2≤ ¥ 3/4≤ Four 1≤ ¥ 1/2≤ ¥ 8-1/16≤ One 3/4≤ ¥ 1/2≤ ¥ 5-1/2≤ Two 3/4≤ ¥ 1/2≤ ¥ 4-1/2≤

Construction of the Rear and Front Section Frames Once the basswood frame-stock has been cut to length, the construction of the frames for the rear and front sections of the camera may proceed. Use the diagrams (see Figures 2.4 and 2.5) as guides for the procedural steps listed below. Also note that a procedure for joining pieces of basswood, using glue, a hammer, finish nails, and

11 1≤ 2

1≤ 2

1≤

10 1≤ 2

1≤ 2

Figure 2.4 Rear section frame. 8≤ ¥ 10≤ sliding box-camera. Front and side views.

1≤ 2

1≤ 816 1≤ 916

1≤ 2

1≤ 2

3 1≤ 2

1≤ 2

1≤

1≤ 2

6≤

43

1≤ 2 1≤ 4

10 1≤ 2

11 1≤ 2

1≤ 2

1≤

3 1≤ 4

1≤ 2

1≤ 816 1≤ 916

1≤ 2

1≤ 2

1≤ 8

1≤ 2

3 7≤ 8

1≤ 2

5 1≤ 2

Figure 2.5 Front section frame. 8≤ ¥ 10≤ sliding box-camera. Front and side views.

a 90° corner-clamp, is given as a separate heading at the end of this chapter (see Figure 2.35). Please refer to it before joining the pieces of basswood. This being done, the procedure is as follows: 1. Taking two of the 1/2≤ ¥ 1/2≤ ¥ 6≤ pieces, join them to three of the 1/2≤ ¥ 1/2≤ ¥ 8-1/16≤ pieces to form the top of the rear section frame. 2. Taking two more of the 1/2≤ ¥ 1/2≤ ¥ 6≤ pieces, join them to one of the 1/2≤ ¥ 1/2≤ ¥ 8-1/16≤ pieces and two of the 1≤ ¥ 1/2≤ ¥ 8-1/16≤ pieces to form the bottom of the rear section frame. 3. Taking six of the 1/2≤ ¥ 1/2≤ ¥ 10-1/2≤ pieces, connect the top and bottom of the rear section frame. 4. Taking two of the 1/2≤ ¥ 1/2≤ ¥ 5-1/2≤ pieces, join them to three of the 1/2≤ ¥ 1/2≤ ¥ 8-1/16≤ pieces to form the top of the front section frame. 5. Taking two more of the 1/2≤ ¥ 1/2≤ ¥ 5-1/2≤ pieces, join them to one of the 1/2≤ ¥ 1/2≤ ¥ 8-1/16≤ pieces and two of the 1≤ ¥ 1/2≤ ¥ 8-1/16≤ pieces to form the bottom of the front section frame. 44

6. Taking the six remaining 1/2≤ ¥ 1/2≤ ¥ 10-1/2≤ pieces, connect the top and bottom of the front section frame. 7. Taking one of the 1/4≤ ¥ 1/2≤ ¥ 8-1/16≤ pieces, add it to the front of the front section frame. 8. Allow the glue to dry for a few hours.

Cutting the Luan With a straight-edge and utility knife, cut a large sheet of 1/8≤ thick Luan plywood to the dimensions listed below. Make light passes with the utility knife, scoring the Luan until the board is cut, rather than trying to cut it completely at once. The number and specific dimensions are as follows:

• • • • • • • • • • • •

One 4-1/2≤ ¥ 9-5/16≤ One 4-7/8≤ ¥ 9-5/16≤ Two 1/2≤ ¥ 9-5/16≤ One 6≤ ¥ 9-5/16≤ One 5-1/2≤ ¥ 9-5/16≤ Two 6≤ ¥ 11-1/2≤ Two 5-1/2≤ ¥ 11-1/2≤ One 9-1/16≤ ¥ 12-1/8≤ One 9-1/16≤ ¥ 2-3/4≤ Two 8≤ ¥ 8-1/4≤ Two 8-1/4≤ ¥ 10-3/16≤ One 10-5/16≤ ¥ 24≤

Attaching the Luan Sides and Focusing Guide-Rails Once the Luan has been cut, the pieces may be glued to the frames of the rear and front sections to make the top, bottom, and sides of the camera. Use the diagrams (see Figures 2.6, 2.7, and 2.8) as guides for the procedural steps that follow: 1. Taking two of the 1/2≤ ¥ 1/2≤ ¥ 6≤ pieces of basswood frame-stock, attach them to one of the 6≤ ¥ 11-1/2≤ pieces of Luan to make the exterior guide-rails, using glue, a hammer, and 1/2≤ wire nails. Spread some glue on the basswood frame-stock, then hammer 1/2≤ wire nails to hold them in place. Space the guide-rails 8-5/16≤ apart, as indicated in the diagram (see Figure 2.6). 2. Repeat step 1 for the other two 1/2≤ ¥ 1/2≤ ¥ 6≤ pieces of basswood frame-stock and the remaining 6≤ ¥ 11-1/2≤ piece of Luan. 3. Taking two of the 1/2≤ ¥ 1/2≤ ¥ 5-1/2≤ pieces of basswood frame-stock, attach them to one of the 5-1/2≤ ¥ 11-1/2≤ pieces of Luan to make the guide-rails. Space the guide-rails 8-5/16≤ apart, as indicated in the diagram (see Figure 2.7). 45

6≤ 5≤ 916

1≤ slot goes here 1≤ 2

1≤ 2

13≤ 32

1≤ 8

4 1≤ 2

113≤ 4 111≤ 2 5≤ 816

1≤ 2

1≤ 8

13≤ 32

1≤ 2

1≤ 2

Figure 2.6 Rear section with sides and focusing guide-rails in place. 8≤ ¥ 10≤ sliding box-camera. Front and side views. Note the removal of 1≤ of the basswood frame-stock at the top of the rear section, as indicated in the final construction procedure.

46

4. Repeat step 3 for the other two 1/2≤ ¥ 1/2≤ ¥ 5-1/2≤ piece of basswood frame-stock and 5-1/2≤ ¥ 11-1/2≤ piece of Luan. 5. Taking the two 6≤ ¥ 11-1/2≤ pieces of Luan, attach them to the sides of the rear section frame using glue, a hammer, and 1/2≤ wire nails. (The rails attached in steps 1 and 2 should be facing outwards, away from the frame.) 6. Taking the 6≤ ¥ 9-5/16≤ piece, attach it to the bottom of the rear section frame. 7. Taking the 4-1/2≤ ¥ 9-5/16≤ piece and one of the 1/2≤ ¥ 9-5/16≤ pieces, attach them to the top of the rear section frame. 8. Taking the two 5-1/2≤ ¥ 11-1/2≤ pieces of Luan, attach them to the sides of the front section frame. (The rails attached in steps 3 and 4 should be facing outwards, away from the frame.) 9. Taking the 5-1/2≤ ¥ 9-5/16≤ piece, attach it to the bottom of the front section frame.

1≤ 2

1≤ 8 slot

goes here

5 1≤ 2 4 7≤ 8

1≤ 2

3≤ 132

1≤ 8

5≤ 916

113≤ 4 111≤ 2 5≤ 816

1≤ 2

1≤ 8

3≤ 132

1≤ 2

1≤ 2

10. Taking the 4-7/8≤ ¥ 9-5/16≤ piece and the remaining 1/2≤ ¥ 9-5/16≤ piece, attach them to the top of the front section frame.

Final Construction Procedure: Camera Body and Camera Platform

Figure 2.7 Front section with sides and focusing guide-rails in place. 8≤ ¥ 10≤ sliding box-camera. Front and side views. Note the removal of 1/8≤ of the basswood frame-stock at the top of the front section, as indicated in the final construction procedure.

After the frames and sides of the front and rear sections have been assembled, and the glue has dried completely, the final construction procedure brings the camera to completion. Once again, for ease of comprehension, this has been divided into six subsections: forming the slots for the film-holder and rising front, installing the rising front, adding the lens board holder, installing the midsection, building the camera platform, and finishing details.

Forming the Slots for the Film-Holder and Rising Front Listed below are the procedural steps for making slots in the rear and front sections of the camera body for the film-holder and rising

47

A

B

C

D

E

Figure 2.8A, B, C, D, and E Stages in attaching Luan plywood to basswood frame-stock. (A) Lining the frame-stock with glue. (B) Partially hammering a 1/2≤ wire nail into the Luan and the frame. (C) Partially hammering as many nails as needed. (D) Tapping the nails flush against the Luan with a nail set. (E) The Luan attached to the frame-stock.

front. Refer to the diagrams (Figures 2.6 and 2.7) for the location of these slots. The steps are as follows: 1. Between the two parallel frame sections at the top of the rear section, make two parallel cuts with a razor saw, 1≤ apart, and on both sides of the camera. Use the adjacent basswood frame as a guide for cutting the wood, and do not allow the blade of the razor saw to cut into the Luan side piece (see Figure 2.6). 2. Once the cuts have been made, remove the two 1≤ sections of basswood frame-stock from the top of the rear section, using a hammer and 3/4≤ chisel. Place the chisel between the basswood frame-stock and the Luan side piece, in order to remove the 1≤ sections. 3. Double-check the fit of the 1≤ slot by sliding the mainframe of the film-holder into it (see Chapter 1). Hand-sand the slot at the top of the rear section as needed, wrapping 60-grit sandpaper around a spare piece of 1/2≤ ¥ 1/2≤ basswood frame-stock. Continue sanding until the component parts fit on the loose side of snug. 4. Repeat steps 1 and 2 to form the slot at the top of the front section of the camera (see Figure 2.7). This time, however, make parallel cuts 1/8≤ apart, and use a hammer and a flathead screwdriver instead of a chisel to knock out the 1/8≤ sections of basswood frame-stock. 5. Double-check the fit of the 1/8≤ slot by sliding the 9-1/16≤ ¥ 12-1/8≤ piece of Luan into it. Sand the faces of the Luan piece as needed, using an orbital sander with 60-grit sandpaper, followed by 150-grit sandpaper until the piece 48

of Luan slides easily in the slot. Hand-sand the edges of the Luan piece as needed, turning down the leading edges and corners with 60-grit paper.

Installing the Rising Front Listed below are the procedural steps for installing the rising front of the camera. Refer to the diagrams (Figures 2.9 and 2.10) as guides for the steps that follow: 1. Mark off a 5≤ ¥ 5≤ square within the 9-1/16≤ ¥ 12-1/8≤ piece of Luan. 2. Cut out and remove the 5≤ ¥ 5≤ square, using a utility knife and a straight-edge. Extending the cuts by 1/8≤ in the corners to facilitate matters is also acceptable. 3. Hand-sand the area surrounding the square opening as needed, using 60-grit sandpaper, followed by 150-grit sandpaper.

Figure 2.9 Cutaway view of the lowered front section with 5≤ ¥ 5≤ square opening and rising front installed. 8≤ ¥ 10≤ sliding box-camera. Front and side views.

1≤ 916 1≤

816

5≤ 11≤ 4

2 1≤ 2

11≤ 4 four drillholes

2 1≤ 2

5≤

12 3≤ 4

2 1≤ 2

3≤ 16

9 161

2 3≤ 4 1≤ 4

¥ 2 43 piece of Luan goes her

49

1≤

12 8 1≤ 4

Figure 2.10 Cutaway view of the raised front section with 5≤ ¥ 5≤ square opening and rising front installed. 8≤ ¥ 10≤ sliding box-camera. Front and side views.

4. Slide the 9-1/16≤ ¥ 12-1/8≤ piece of Luan back into the front section of the camera completely, so that the 5≤ ¥ 5≤ square opening is centered with regard to the front. 5. Using glue and a hammer, attach the remaining 1/4≤ ¥ 1/2≤ ¥ 8-1/16≤ piece of basswood frame-stock to the backside of the 9-1/16≤ ¥ 12-1/8≤ piece of Luan. Here it is necessary to raise the Luan slightly in order to hold the basswood in place with two C-clamps until the glue has dried. 6. Taking the 9-1/16≤ ¥ 2-3/4≤ piece of Luan, attach it to the front of the front section frame, using glue, a hammer, and 1/2≤ wire nails. Allow to dry.

Adding the Lens-Board Holder Once the glue in the front section has dried completely, move the 9-1/16≤ ¥ 12-1/8≤ front piece of Luan up and down to check its 50

1" screw post expanded to

1 5 "

1 1 " 8

1" 2

3" 8

1" 2

1" 4

3" 8

2

1" 4

1" 2

4

1 " 2

3" 4

1" 2

Four 1" Screw posts

rising ability. It should be able to rise about 1-3/4≤. This being done, the pieces of basswood needed to hold the lens board in place may be attached. Referring to the diagrams (see Figures 2.9 and 2.11) for the exact locations of the pieces of basswood frame-stock and the drill-holes, the lens-board holder is installed in the following way:

Figure 2.11 Cutaway view of the lowered front section with lens board holder installed. 8≤ ¥ 10≤ sliding boxcamera. Front and side views.

1. Using two C-clamps to hold the basswood in place, attach the two remaining pieces of 1/2≤ ¥ 1/2≤ ¥ 5-1/2≤ basswood frame-stock to either side of the bottom edge of the 5≤ ¥ 5≤ square opening. Leave the C-clamps in place until the glue has dried. 2. Using two C-clamps to hold the basswood in place, attach the two pieces of 3/4≤ ¥ 1/2≤ ¥ 4-1/2≤ basswood framestock to the rear of the side edges of the 5≤ ¥ 5≤ square opening. Leave the C-clamps in place until the glue has dried. 3. Using two C-clamps to hold the basswood in place, attach the piece of 3/4≤ ¥ 1/2≤ ¥ 5-1/2≤ basswood frame-stock 51

to the rear of the top edge of the 5≤ ¥ 5≤ square opening. Leave the C-clamps in place until the glue has dried. 4. Once the glue has dried, and the C-clamps have been removed, drill four 3/16≤ holes into the rising front of the camera, using a portable power drill and a 3/16≤ drill bit. 5. Drill one 3/16≤ hole into each of the 1/2≤ ¥ 1/2≤ ¥ 3/4≤ pieces of basswood frame-stock, so that the 1/2≤ ¥ 1/2≤ ¥ 3/4≤ pieces line up with the holes drilled in step 4. 6. Attach the 1/2≤ ¥ 1/2≤ ¥ 3/4≤ pieces to the front section of the camera, by separating the 1≤ aluminum screw-posts and sliding them in the 3/16≤ holes. In screwing the posts back together again, do not tighten them so much that the 1/2≤ ¥ 1/2≤ ¥ 3/4≤ pieces are unable to turn freely.

Installing the Mid-Section With the rising front in place and operative, the rear and front sections may be connected via the midsection. This involves the assembly of four side pieces, installation into the front and rear sections, and gluing them with vinyl adhesive caulk. Referring to the diagrams (see Figures 2.12 to 2.16), this is achieved in the following way: 1. Using glue, a hammer, and 1/2≤ wire nails, attach two 1/2≤ ¥ 1/2≤ ¥ 8≤ pieces of basswood to each of the 8≤ ¥ 8-1/4≤ pieces of Luan, to form the top and bottom of the midsection (see Figure 2.12). 2. Repeat step 1, attaching two 1/2≤ ¥ 1/2≤ ¥ 10-7/16≤ pieces of basswood to each of the 8-1/4≤ ¥ 10-3/16≤ pieces of Luan, to form the sides of the midsection (see Figure 2.13). 3. Once the glue in the top, bottom, and side pieces has dried, position them in the front and rear sections of the camera so as to connect them (see Figure 2.14). Check the movement of the front and rear sections, holding the side pieces in place. The camera should be able to expand and contract to the limits of the rear, front, and middle sections. Remove the side pieces, sanding and rechecking the component parts as needed, until the camera body can expand and contract completely (see Figures 2.15 and 2.16). 4. Once the fit of the midsection pieces has been verified, leave them in place. With the camera fully extended, use a caulk gun to apply four lines of black vinyl adhesive caulk in the interior of the midsection, exactly where the side pieces come into contact with each other. After applying each line of adhesive, spread it out evenly with your fingers to avoid any light-leaks. Allow the vinyl adhesive caulk in the midsection to dry for a few hours. WASH YOUR FINGERS WITH HOT WATER AND SOAP IMMEDIATELY AFTER WORKING WITH THE CAULK. 52

8"

Figure 2.12 Midsection, top and bottom piece. 8≤ ¥ 10≤ sliding boxcamera. Bottom and side views (bottom piece).

1 " 4

1" 2

5" 8

1" 8

8

7 1" 2

1 " 4

1" 2

3 ≤

10 16

1≤ 8

10 16

7 ≤

1≤ 8

Figure 2.13 Midsection, side piece. 8≤ ¥ 10≤ sliding box-camera. Front and side views (right-hand side piece).

1≤ 2 1≤ 8 5≤ 8

1≤ 2

7

1 ≤ 4

8

1 ≤ 4

1≤ 2

9˝ 8˝ 1≤ 8

1≤ 2

8

1 ≤ 4

7

1 ≤ 4

1≤ 2

3 ≤

10 16

7 ≤

10 16

1≤ 8

11 16

7 ≤

1≤ 8

7

3 ≤ 4

1≤ 8

Figure 2.14 Orientation of the top, bottom, and sides of the midsection, as installed in the front and rear sections. 8≤ ¥ 10≤ sliding boxcamera. Front and side views.

5. Once the caulk has dried completely, check the fit of the midsection once again by expanding and contracting the rear and front sections. Everything should move freely.

Building the Camera Platform Listed below are the steps in constructing the platform for the camera. Refer to the diagram (see Figure 2.17) as a guide for the steps that follow: 1. With a pencil, center and mark off a 3-1/2≤-wide strip along the length of both sides of the 10-5/16≤ ¥ 24≤ piece of Luan. 2. Using glue, a hammer, and 1/2≤ wire nails, attach the 1/2≤ ¥ 1/2≤ ¥ 24≤ pieces of basswood to the 10-5/16≤ ¥ 24≤ piece of Luan. 3. Repeat step 2, attaching the 1/2≤ ¥ 1/2≤ ¥ 9-5/16≤ pieces of basswood to the 10-5/16≤ ¥ 24≤ piece of Luan. 54

Figure 2.15 Cutaway view of the contracted front and rear sections, showing the hidden position of the installed midsection. 8≤ ¥ 10≤ sliding box-camera. Side view.

1≤

84 1≤

52

6≤ 1≤ 11 2

4. Using a hand-saw, cut a 24≤ length of 1 ¥ 4 pine (the actual dimensions of the pine as sold are 3/4≤ ¥ 3-1/2≤). 5. Taking the 24≤ length of pine, glue it on the side of the Luan without the basswood frame-stock, between the pencil lines marked out in step 1. Hold the pine in place temporarily with two C-clamps, until a number of 1/2≤ wire nails have been hammered into it between the pencil lines marked out on the other side. 6. Using a portable power-drill and a 3/8≤ drill-bit, drill three 3/8≤-wide holes 1/2≤ deep into the pine. Then line the sides of three 3/8≤-wide, 1/4-20 bushings with glue and screw the bushings into the drilled holes in the pine with a flathead screwdriver. Allow to dry for a few hours.

Finishing Details Once the glue in the camera body and platform has dried, a few details remain before the construction of the camera is brought to 55

17 34 ≤ 1≤

52

1≤

64

6≤

1≤

84

Figure 2.16 Cutaway view of the expanded front and rear sections, showing the hidden position of the midsection. 8≤ ¥ 10≤ sliding boxcamera. Side view.

conclusion. Refer to the diagrams (see Figures 2.17 and 2.18) for visual examples concerning the following procedures: 1. Using a razor saw and miter box, cut two 24≤ lengths from two yardsticks, taking care that the resultant metric markings read from 0 mm to 610 mm. 2. Taking a straight-edge and a utility knife, split the length of the 24≤ lengths of yardstick so that they are 5/8≤ wide and include the metric markings. 3. With a 1/2≤ brush, paint the metric side 5/8≤ ¥ 24≤ yardstick sections with polyurethane varnish, leaving the side with the inch markings unpainted. Allow to dry for a few hours. ALWAYS PAINT IN AN AREA WHERE THERE IS ADEQUATE VENTILATION. WEAR RUBBER OR EXAMINATION GLOVES WHEN PAINTING.

56

5≤

1016

1≤ 2

1≤ 2

5≤

916

1≤

32

6˝ 6˝ 5≤

5≤

532

bushings

3≤ 4

1≤ 8

1≤ 2

1≤ 2

532

Locations for the three

1 –20 4

6˝

6˝

23˝

1≤ 2

24˝

1≤ 2

4. Clean the brush with turpentine, followed by soap and soap and water. 5. Double-check the fit of the platform by attaching it to a tripod, testing each of the bushings. 6. Leaving the platform on the tripod, place the camera body inside of the platform’s basswood frame so that the camera is in a vertical position. Check the fit of the camera and platform by expanding and contracting the camera body. It should be able to expand and contract smoothly. Sand the camera body as needed until the fit is smooth. 7. Turn the camera body onto each of its sides, so that it is in a horizontal position, to check the fit of the guide-rails. Again, it should be able to expand and contract smoothly. Sand the platform and camera body as needed until the fit is smooth. 8. Once the fit has been determined, remove the camera body and platform from the tripod. 9. Paint all of the exposed surfaces of the camera body and platform flat black. Use a 2-1/2≤–3≤ brush for the larger areas and a 1/2≤ brush for the more difficult locations. No visible area should remain unpainted either inside or outside the camera. Slide the rising front up and down and expand the camera body as needed, painting everything entirely. Allow to dry for a few hours. 10. Clean the brushes with turpentine, followed by soap and water. 11. When dry, touch up any additional areas as needed and leave to dry again. 12. Once the paint on the platform has dried, attach one of the yardstick sections from steps 1 to 3 to one of the 24≤ edges of the platform using glue, a hammer and 1/2≤ nails. Zero (0) mm should be located at the front of the platform, and 610 mm at the rear. This may necessitate turning one yardstick section upside-down. 13. Repeat step 12 for the other 24≤ edge of the platform. Once again, 0 mm should be located at the front of the platform, and 610 mm at the rear. This may necessitate turning one yardstick section upside-down.

3≤ 8

Figure 2.17 Camera platform. 8≤ ¥ 10≤ sliding box-camera. Bottom and front views.

57

Using the Camera Use of the sliding box-camera presupposes that the lens, focusing screen, and wet-paper process film-holder have also been built (see Chapters 1 and 3). This being the case, the camera is ready to be used. Directions for using the camera have been divided into the following subsections: attaching the camera to a tripod, installing the lens, focusing, and making the exposure.

Attaching the Camera to a Tripod The steps involved in attaching a camera to a tripod are listed below. Refer to the diagram (see Figure 2.18) in relation to the following procedural steps: 1. Select a point of view and set up the tripod. 2. Connect the camera platform to the tripod, via one of the 1/4-20 bushings. The choice of which bushing to use depends on the weight of the lens and film-holder, and how far the front and back of the camera are extended. 3. Adjust the head of the tripod so that the platform is approximately level; then tighten everything down. 4. Place the camera body on the platform base. If the view is to be vertical, the camera body is placed in an upright position so that the bottom rests between the rails of the platform. If the view is to be horizontal, the camera body is placed on one of its sides, so that the guide-rails rest between the rails of the platform.

Installing the Lens Any lens with a focal length falling within the camera body’s focusing range can be used, so long as it is mounted on a 5≤ ¥ 5≤ ¥ 1/8≤ lens board (see Chapter 3). To install the lens, refer to the diagram (see Figure 2.19) in relation to the following procedural steps: 1. Turn the 3/4≤ pieces of basswood on the front of the camera away from the square opening so that the ledges of the lens board holder are fully accessible. 2. Holding the lens barrel, slide the bottom of the lens board into the groove at the bottom of the square opening so that it rests securely. 3. Push the rest of the lens board towards the camera so that it rests against the ledges of the lens board holder. 4. Turn the 3/4≤ pieces of basswood so that they are holding the lens board in place. Removal of the lens proceeds in the opposite way. Also note that with repeated use, the screw posts attaching the 3/4≤ pieces of bass58

Figure 2.18A, B, C, and D Setting up the sliding box-camera. (A) The head of the tripod, minus the platform and camera body. (B) The platform connected to the tripod. (C) The camera body placed upon the platform in a vertical position. (D) The camera body placed upon the platform in a horizontal position.

A

B

C

D

wood to the front of the camera will loosen. To remedy this, tighten them occasionally with a flathead screwdriver as needed.

Focusing With the lens installed, the camera is ready to be focused using the focusing screen. This is achieved in relation to the following procedural steps: 1. Slide the focusing screen into the slot at the rear of the camera until it is fully in place. 59

Figure 2.19A, B, C, and D Installing a lens in the sliding boxcamera. (A) The front of the camera with the 3/4≤ pieces of basswood turned away from the square opening. (B) Sliding the lens board into the groove at the bottom of the lens board holder. (C) Turning the 3/4≤ basswood pieces in order to hold the lens board in place. (D) The lens installed and ready for use.

A

B

C

D

2. Remove both of the dark-slides from the main-frame of the focusing screen. Bring the subject into focus by moving either the front or back of the camera, or a combination of both, until an inverted image is visibly focused upon the focusing screen. Here it is necessary to use a dark-cloth (such as two square yards of black velvet) and a focusing loupe (8¥) in order to see the image more easily and check the focus of specific details. 3. Readjust the composition and focus as needed. Change the f-stops in the lens to increase or diminish depth of field as needed (see Chapter 3).

Making the Exposure Once the camera has been focused, the exposure is ready to be made. Refer to the diagram (see Figure 2.20), in relation to the following procedural steps: 1. With the desired view in focus, attach two C-clamps to the platform rails on either side and in contact with the front of the camera. 2. Attach two C-clamps to the platform rails on either side and in contact with the rear of the camera. Note: steps 1 and 2 are preventive measures to avoid losing the focus in switching from the focusing screen to the film-holder. If this occurs, the camera is simply expanded back to where the C-clamps are located, which ensures that the camera returns to its original position. 60

A

B

C

D

E

F

G

Figure 2.20A, B, C, D, E, F, and G Making the exposure with the sliding box-camera. (A) Adding Cclamps to the platform rails against both ends of the camera body. (B) Removing the focusing screen. (C) Installing the film-holder. (D) Removing the dark-slide with the lens-cap in place. (E) Resting the dark-slide on top of the film-holder. (F) Removing the lens-cap, in order to make the exposure. (G) The exposure being made.

3. Remove the focusing screen from the camera body. 4. Slide the film-holder into the slot at the back of camera body, making sure that the dark-slides remain in place and that a side of the film-holder with an unexposed negative is facing the lens. 5. Slide the lens-cap on the lens. 6. Double-check to make sure that the back and front of the camera are still against the C-clamps. 7. Remove the dark-slide facing the lens. Here it is a good idea to cover the open slot from which the dark-slide has been removed, which prevents the possibility of a light leak. Either lay the dark-slide down on top of the open slot or turn the dark-slide upside-down, reinserting the short end at the top of the dark-slide into the slot once again. 8. Make the exposure by removing the lens-cap from the lens and keeping track of the exposure time with a stop61

watch. Once the requisite amount of time has elapsed, slide the lens-cap back on the lens. 9. After the exposure has been made, slide the dark-slide back into the film-holder, having turned it so that the “Exposed” notation is in view. This prevents accidentally reexposing the negative afterwards (see Chapter 1). 10. With the dark-slide in place, remove the film-holder from the camera. Note concerning steps 1 and 2: if a lens which is uncorrected for chromatic aberration is used, the distance between the front and back of the camera should be measured after focusing the image using the millimeter markings on the sides of the platform. Multiply this distance by .975 to arrive at the focusing adjustment for the uncorrected lens. Prior to making the adjustment, attach two Cclamps on the platform rails against one of the ends of the camera body. Keeping this end against the C-clamps, slide the other end of the camera inwards until the correction is made. This is followed by the placement of two C-clamps at the adjusted end of the camera. For example, if, after focusing, the front of the camera was at 115 mm and the back of the camera was at 515 mm, 115 mm would be subtracted from 515 mm to arrive at a distance of 400 mm. The resultant 400 mm would be multiplied by .975 to arrive at 390. Two C-clamps having been attached at the front of the camera, the rear would then be brought forward 10 mm to the 505 mm marking, followed by attaching two other C-clamps at the rear of the camera. Visually, the image will appear soft, but the negative will nevertheless be in focus (see Chapter 3 for more on chromatic aberration).

Perspective Correction In composing the image, it is also important to determine whether it should be corrected for perspective along the vertical axis. This has to do with the vertical lines of a given scene, which may be depicted as either running straight up and down, parallel to the picture frame, or converging. When the vertical lines are running parallel to the picture frame, the image is said to be corrected. Most mid-nineteenth century photographers corrected for perspective along the vertical axis, and today, many view-camera operators also adopt this principle. Using a box-camera with a rising front, perspective correction along the vertical axis is simply achieved. Place a torpedo level on top of the camera body so that it is running parallel with the long dimension of the platform, and adjust the tripod until the camera reads level. Next, place the torpedo level at the rear of the camera body—once again on top—so that this time it is running parallel with the film plane. Once again, adjust the tripod until the camera reads level. In this way, the camera is

62

corrected for perspective along the vertical axis, and the vertical lines in the resulting scene will be represented as running parallel to the picture frame. The rising front of the camera body has also been added with perspective correction in mind. It is especially useful in scenes where the camera would otherwise need to be tilted up, or skywards, as is often the case, for example, in photographing monumental architecture. In using the rising front, rather than tilting the camera up, the view can be adjusted or raised while still maintaining the level positioning of the camera. To do this, rather than tilting the camera up, raise the sliding front of the camera up until the desired view is obtained. To keep the sliding front in the raised position, attach a Cclamp on the frame of the camera just beneath the raised front. Note: with the camera turned on its side for a horizontal view, the rising function works from side to side, rather than up and down. Here it is used to adjust two-dimensional subjects, viewed frontally, so that the horizontal lines of the image are rendered parallel to the picture frame.

THE FOLDING-CAMERA The 10≤ ¥ 12≤ folding-camera, as constructed according to the procedural steps described below, is intended for use with a dry, waxed-paper process film-holder and focusing screen (see Chapter 1). Rather than moving the front and back of the camera, focus is achieved by moving the lens tube back and forth in a brass tube until a focused image is visible on the focusing screen (see Chapter 3 for more on making the brass tube). Expanded, the camera body measures 13-5/16≤ ¥ 11-1/4≤ ¥ 21-21/32≤ with the removable film-holder and lens board providing the necessary structural rigidity when in use. When folded up, the camera body measures 13-5/16≤ ¥ 2-1/2≤ ¥ 21-21/32≤. It is connected directly to a tripod. This camera has not been designed with a direct source in mind. It is sort of a hybrid of two folding-camera designs, one being a pocket camera obscura from the early 1840s and the other being Ottewill’s folding-camera from the early 1850s (see Figure 2.21).10 Starting from the original illustrations, I have arrived at what I consider my own design. Once again, this design has mostly been determined by a desire to keep things cheap, simple, and easy to make. And while the construction procedures given below are for an 10≤ ¥ 12≤ format camera, the design may also be modified to accommodate for larger or smaller formats, should you prefer this possibility. The important thing is to first decide upon a format size prior to construction, from which a corresponding lens focal length can be determined, and then adjust the dimensions of the wood given here to match the film-holder and focal length in question (see Chapter 1 for more on format sizes).

63

Figure 2.21A and B Two midnineteenth-century folding-camera designs. (A) Detail from a cover illustration, The Magazine of Science (London, 1842). (B) Ottewill’s foldingcamera, reprinted from W. [Marcus] Sparling, Theory and Practice of the Photographic Art (1853; reprint, New York, 1973), 42, fig. 42.

A

B

As given in the construction example below, the camera is intended for use with a lens having a focal length measuring approximately 425 mm. Other lens focal lengths may necessitate a lengthening or shortening of the camera. Otherwise, the construction procedures should remain largely the same. With careful measurement, both the folding-camera and filmholder can be built separately. Nevertheless, it is recommended that the construction of the camera occur in tandem with the construction of the film-holder (see Chapter 1). This is to ensure accuracy of fit with regard to the sanding of the film-holder and camera body, and the placement of the light-traps on the film-holder. The construction procedures given below have been divided into two major sections. The first section, or initial construction procedure, pertains to making the frame and exterior faces of the camera body. This should occur in tandem with the initial construction of the mainframe of the film-holder. Once the fit of both component parts has been verified, the second section, or final construction procedure, may proceed independently. 64

Initial Construction Procedure The initial procedure for constructing the front and rear sections of the folding-camera is given below. For ease of comprehension, this has been divided into three subsections: cutting basswood framestock to size, cutting the Luan, and forming the top, bottom, and sides.

Cutting Basswood Frame-Stock to Size Cut 2¢ to 3¢ lengths of basswood frame-stock to the following number of specified lengths using a modeler’s razor saw and miter box:

• • • • • •

Sixteen 1/2≤ ¥ 1/2≤ ¥ 8-5/16≤ Four 1/2≤ ¥ 1/2≤ ¥ 13-1/16≤ Four 1/2≤¥ 1/2≤ ¥ 19-5/8≤ Eight 1/2≤ ¥ 1/2≤ ¥ 5≤ Twelve 1≤ ¥ 1/2≤ ¥ 4-1/2≤ Six 1≤ ¥ 1/2≤ ¥ 13-1/16≤

Diameters of basswood dowels are also determined by the manufacturer, and sold in the form of 3¢ and 4¢ lengths. As very little dowel material will be used in the construction of the folding-camera, one 3¢ length of a 3/16≤ dowel will be sufficient. Cut the dowel with a utility knife, rather than a saw, in order to avoid tearing the ends of the dowel. Mark a line on the length of the dowel where the intended cut is to be made, and then roll the dowel beneath the razor’s edge at the indicated mark, gradually increasing the pressure of the utility knife until the cut is made. Using this suggested cutting method, cut the following basswood dowel sections:

• Ten 3/16≤ ¥ 7/8≤ • Two 3/16≤ ¥ 5/8≤ Cutting the Luan With a straight-edge and utility knife, cut a large sheet of 1/8≤ thick Luan plywood to the dimensions listed below. Make light passes with the utility knife, scoring the Luan until the board is cut, rather than trying to cut it completely at once. The number and specific dimensions are as follows:

• • • •

One 13-5/16≤ ¥ 19-5/8≤ One 13-5/16≤ ¥ 21-21/32≤ Four 5-1/2≤ ¥ 21-21/32≤ Two 1/2≤ ¥ 13-5/16≤ 65

Forming the Top, Bottom, and Sides Listed below are the steps involved in constructing the top, bottom, and sides of the folding-camera, which should be followed in relation to the diagrams (see Figures 2.22 to 2.25). Ideally, this construction should take place in tandem with the initial construction of the dry, waxed-paper film-holder (see Chapter 1). The procedure is as follows: 1. Taking two of the 1/2≤ ¥ 1/2≤ ¥ 13-1/16≤ pieces of basswood frame-stock, three of the 1≤ ¥ 1/2≤ ¥ 13-1/16≤ pieces, and four of the 1/2≤ ¥ 1/2≤ ¥ 8-5/16≤ pieces, attach them to the 13-5/16≤ ¥ 21-21/32≤ piece of Luan using glue, a hammer, and 1/2≤ wire nails, according to the diagram (see Figure 2.22). This is to form the bottom of the camera. 2. Taking the three remaining 1≤ ¥ 1/2≤ ¥ 13-1/16≤ pieces of basswood frame-stock and four more of the 1/2≤ ¥ 1/2≤ ¥ 8-5/16≤ pieces, attach them to the 13-5/16≤ ¥ 19-5/8≤ piece of Luan using glue, a hammer, and 1/2≤ wire nails, according to the diagram (see Figure 2.23). This is to form the top of the camera. 3. Taking two of the 5-1/2≤ ¥ 21-1/32≤ pieces of Luan and a 2≤ ¥ 24≤ piece of black ribbon or book-cloth, glue the ribbon to the Luan pieces to form one of the hinged side pieces (see Figures 2.24 and 2.25). Note: book-cloth will necessitate gluing two layers to make it light-tight. 4. Repeat step 3, forming the other hinged side piece. Allow both pieces to dry for a few hours beneath heavy weights. 5. Once the glue has dried, remove the excess ribbon or book-cloth with a utility knife and metal straight-edge. 6. Taking six of the 1≤ ¥ 1/2≤ ¥ 4-1/2≤ pieces of basswood frame-stock, two of the 1/2≤ ¥ 1/2≤ ¥ 5≤ pieces, four of the 1/2≤ ¥ 1/2≤ ¥ 8-5/16≤ pieces, and two of the 1/2≤ ¥ 1/2≤ ¥ 19-5/8≤ pieces, attach them to one of the hinged side pieces glued in steps 3 to 5, according to the diagram (see Figure 2.25). 7. Repeat step 6, with the other hinged side piece. (Note: prior to the final installation of a dowel section, both side pieces are identical.) 8. Allow the side pieces to dry for a few hours.

Final Construction Procedure After the bottom, top, and side sections have been assembled, and the glue has dried completely, the final construction procedure brings the camera to completion. Here it is recommended that the initial construction of the main-frame of the dry, waxed-paper filmholder from Chapter 1 be completed, as well as the folding-camera lens board assembly from Chapter 3, in order to ensure accuracy of 66

67

1

1" 2

Figure 2.22

1"

8

5"

8

8

1"

1316 " 1316 "

5

1"

8

8

1"

5 8 16 "

Bottom section. 10≤ ¥ 12≤ folding-camera. Top and side views.

1" 2

1"

1"

21

21 32 " 5

8 16 "

1"

29 " 32

1" 2

5 ≤

8 16

1˝

13 16

68 1 ≤

1˝

1≤ 8 1≤ 8

Top section. 10≤ ¥ 12≤ folding-camera. Side and bottom views.

5 ≤

8 16

13 16

Figure 2.23

1˝

5 ≤

19 8

5≤ 8

5 ≤ 1≤ 8 1≤ 2

A

B

C

D

E

F

fit. For ease of comprehension, this has been divided into four subsections: making the removable front and rear sections, connecting the top, bottom, and side sections, adding dowels and drill-holes, and finishing details.

Making the Removable Front and Rear Sections In order to be able to remove the lens board and film-holder, as well as to sufficiently block out light, the construction of a few removable pieces is necessary. Refer to the diagrams (see Figures 2.26 to 2.29), in relation to the following construction procedures:

Figure 2.24A, B, C, D, E, and F Stages in making a hinge with ribbon. (A) The two Luan pieces and the twofoot length of ribbon. (B) Lining one side of the ribbon with glue. (C) Positioning the ribbon on the pieces of Luan. (D) Allowing the glue to dry for a few hours with a weight on top. (E) Trimming away the excess ribbon. (F) The finished ribbon hinge.

1. Taking a 1/2≤ ¥ 1/2≤ ¥ 13-1/16≤ length of basswood frame-stock, drill one 3/16≤ hole completely through the basswood, approximately 1/4≤ from each end, as indicated in the diagram (see Figure 2.26). Then attach a 1/2≤ ¥ 135/16≤ piece of Luan to the basswood frame-stock using a hammer, glue, and 1/2≤ wire nails. This forms a removable rear section that helps to hold the film-holder in place. 2. Taking the remaining 1/2≤ ¥ 1/2≤ ¥ 13-1/16≤ length of basswood frame-stock, drill one 3/16≤ hole approximately 1/4≤ deep into each end, as indicated in the diagram (see Figure 2.27). Then attach the remaining 1/2≤ ¥ 13-5/16≤ piece of Luan to the basswood frame-stock using a hammer, glue, and 1/2≤ wire nails. Follow this by sliding— not gluing—a 7/8≤ length of 3/16≤ dowel into each end. This forms a removable front section that helps to hold the lens board in place. 3. Taking the remaining four 1/2≤ ¥ 1/2≤ ¥ 5≤ lengths of basswood frame-stock, drill one 3/16≤ hole approximately 69

4 1≤ 2

4 1≤ 2

3≤ 16

3≤ 16

1≤ 4

3≤ 8 5≤ 8

5≤ 8

1≤

3≤ 8

5≤ 8 16

19 5≤ 8 2121≤ 32

1≤

5≤ 8 16

1≤

3≤ 16

dowel

29≤ 32

5≤ 8

1≤ 4

1≤ 2

1≤ 2

2≤

1≤ 2

5≤

5≤

3≤ 8 1≤ 4

1≤ 4

11≤

1≤ 2

1≤ 2

1≤ 2

1≤ 2

1≤ 2

Figure 2.25 Side section. 10≤ ¥ 12≤ folding-camera. Side and rear views. Note: with the exception of the later placement of the 3/16≤ dowel and the five 3/16≤ drillholes, the two side sections are identical.

5 1≤ 2

5 1≤ 2

1≤ 4

3≤ 16

drill holes

drill holes

drill holes

5"

8

1"

8

1" 1"

5

8

13 16 "

1" 4

1"

1" 3" drill 16

hole

5

13 16 "

1"

4

8

1" 4 1" 1"

2

hole

Removable rear section. 10≤ ¥ 12≤ folding-camera. Rear and bottom views.

Figure 2.26

8

2

4

3" drill 16

5"

2

1

13 16 "

1" 8

4

1" 4

4

1"

7" 1"

1"

1

13 16 "

8

4

1"

2

8

8

5" 8 7" 8 1"

3"

8

12 16 "

16

1"

dowel

9

5"

5

14 16 "

Figure 2.27

Removable front section. 10≤ ¥ 12≤ folding-camera. Front and bottom views.

1≤ 4

1/4≤ deep, approximately 1/4≤ from each end. Then glue a 7/8≤ length of 3/16≤ dowel in each drilled hole, as indicated in the diagrams (see Figures 2.28 and 2.29). This is to form four removable front sections that help to prevent extraneous light from entering the camera. Allow to dry for a few hours.

4 1≤ 2 1≤ 4

1. Cut eight 7/8≤ ¥ 8-1/8≤ pieces of black ribbon or bookcloth. 2. Referring to the diagrams (see Figures 2.30 and 2.31), glue four of the pieces of ribbon from step 1, attaching one of the side sections to the top and bottom sections. Allow the assembly to dry for a few hours, keeping the top and bottom pieces propped up vertically, and placing weights on top of the pieces of ribbon. 3. Once the glue from step 2 has dried, turn the assembly over and attach the top and bottom sections to the other side section using the remaining four pieces of ribbon from step 1. Allow the assembly to dry for a few hours, again

5≤

The following steps connect the top, bottom, and sides of the camera by means of eight cloth hinges:

3≤ dowels 16

Connecting the Top, Bottom, and Side Sections

7≤ 8 1≤ 1≤ 5≤ 8 4 4 1≤ 2

1≤ 1≤ 4 4 1≤ 2

1 1≤ 8

Figure 2.28 Removable front section. 10≤ ¥ 12≤ folding-camera. Front and side views.

71

A Figure 2.29A, B, and C Stages in making a removable front section. (A) A piece of basswood frame-stock, cut to length. (B) Two drill holes added. (C) The dowels glued in place.

B

C

keeping the top and bottom pieces propped up vertically, and placing weights on the pieces of ribbon. Note: bookcloth will necessitate gluing a second layer, in order to make it light-tight.

Adding Dowels and Drill-Holes Once the glue in the hinges has dried, the following steps allow the removable front and rear sections to be connected to the camera: 1. Check the folding ability of the camera. It should be able to fold and unfold easily. 2. With the camera unfolded, slide the main-frame of the film-holder from Chapter 1 into the slot at the rear of the camera to keep it from collapsing. The fit should be just on the loose side of snug. Sand and recheck the fit as needed. 3. With the main-frame of the film holder installed, drill a 3/16≤ pilot hole 1/4≤ deep at the top of the basswood frame-stock at the rear of one side of the camera, according to the diagrams (see Figures 2.25 and 2.32). 4. Place a drop of glue in the hole formed in step 3, and install a 5/8≤ length of a 3/16≤ dowel. Once the dowel is in place, approximately 3/8≤ of the dowel should protrude up from the basswood frame-stock. 5. Repeat steps 3 and 4, installing an identically sized dowel on the other side of the camera. 6. Turn the camera onto one of its sides and drill five 3/16≤ holes at the front of the camera, according to the diagram (see Figure 2.25). 7. Repeat step 6, turning the camera onto its other side and drilling five more holes, opposite the first, at the front of the camera. 8. Using a putty knife, fill any cracks in the wood with putty and allow to dry for a few hours.

72

1≤ 8

1≤

11 4

1 ≤

12 4

Figure 2.30

12

3≤ 8

8

1 ≤ 8

8

ribbon

1 ≤ 8

Unfolded and folded positions. 10≤ ¥ 12≤ folding-camera. Side view.

1 ≤ 2

11˝

2

1≤ 8

1≤ 8

3≤ 8

21≤ 21 32 5 ≤ 19 8

1 – 20 Bushing 4

8

1 ≤ 8

8

ribbon

1 ≤ 8 5≤ 8

1≤ 2

7≤ 8

7≤ 8

12 1≤ 4

12 3≤ 8

1≤ 13 16

1≤ 2

2 1≤ 2

5≤ 13 16

3≤ 8

Figure 2.31 Unfolded and folded positions. 10≤ ¥ 12≤ folding-camera. Front view.

1 4

-20 Bushing

Finishing Details The following steps bring the construction of the folding-camera to completion: 1. With the camera unfolded and the main-frame installed, check the fit of the 13-1/16≤ ¥ 12-1/8≤ Luan lens board from Chapter 3 by sliding it into the 1/8≤ groove at the

74

Figure 2.32A and B Installing a 3/16≤ dowel at the rear of the camera. (A) Location of the drill-hole with the main-frame of the filmholder in place. (B) The dowel glued in place.

A

B

2. 3.

4.

5.

6.

bottom of the front of the camera. The fit should just be on the loose side of snug. Sand and refit as needed. Remove the main-frame of the film-holder and lens board. Then fold up the camera completely. Drill a 3/8≤ hole 1/2≤ deep into the bottom of the camera, according to the diagrams (see Figures 2.30 and 2.31). Line the threads of a 1/4-20 brass bushing with wood glue, and then screw it into the drilled hole with a flathead screwdriver. This enables the camera to be connected to a tripod. Using a 2-1/2≤–3≤ brush, paint all of the exterior surfaces of the camera, except the ribbon hinges, flat black. Paint all exterior surfaces of the removable front and rear sections flat black as well, using a 1/2≤ brush. Then allow the paint to dry for a few hours. Clean the brushes using turpentine, followed by soap and water. ALWAYS PAINT IN AN AREA WHERE THERE IS ADEQUATE VENTILATION. WEAR RUBBER OR EXAMINATION GLOVES WHEN PAINTING. Once the paint on the exterior surfaces has dried, unfold the camera and paint the interior surfaces flat black as well. Use a 2-1/2≤ to 3≤ brush for the larger areas and a 1/2≤ and a no. 4 brush for the smaller areas. Once again, avoid painting the interior ribbon hinges, as this weakens the glue. Note: if you are using book-cloth as a hinge material, paint it with black acrylic gesso once the enamel paint has dried. Once the paint has dried, double-check to see if any areas were missed the first time; repaint as needed, allowing to dry for a few hours.

Using the Folding-Camera Once the paint on the folding-camera has dried, and the fit of its component parts has been verified, it is ready to be used. Refer to the diagram (see Figure 2.33) for the steps involved in setting up the camera in order to make an exposure. Apart from the fact that focusing is achieved by sliding the lens barrel back and forth, rather than the camera body, all other aspects of making the exposure are iden75

F

A

B G

C

D H

Figure 2.33A, B, C, D, E, F, G, H, and I Setting up the foldingcamera to make an exposure. (A) The tripod head, minus the camera. (B) The camera in a folded position attached to the tripod. (C) The camera unfolded with the focusing screen installed at the rear. (D) Installing the lens board by leaning it away and sliding it into the groove at the bottom of the camera. (E) Installing one of the removable front sections. (F) Installing a dowel in the topmost front section. (G) The folding-camera completely assembled. (H) Adjusting the focus by moving the lens barrel. (I) Tightening the hoseclamp once the composition and focus have been determined.

E

I

tical to the sliding box-camera. For a vertical view, the tripod head is turned so that the camera is oriented on its side (see Figure 2.34).

WOOD JOINING PROCEDURE Listed below is a joining procedure for basswood frame-stock so that any number of pieces of wood may be quickly glued together to form a two or three-dimensional framing structure. Refer to the

76

Figure 2.34A and B Horizontal and vertical views with the foldingcamera. (A) The camera as attached to the tripod for a horizontal view. (B) The camera as attached to the tripod for a vertical view.

A

B

illustration (see Figure 2.35) in relation to the following procedural steps: 1. Line the two surfaces of wood to be joined with glue, and bring the two surfaces together with a 90° corner-clamp to ensure that they are square. Tighten the corner-clamp until the pieces are in contact with each other, flush, and held securely. 2. Cut off the head of a 1≤ finish nail with a pair of wire cutters, and place the rest of the nail into a power drill. 3. Using the nail as a drill bit, drill a pilot hole through one of the joined pieces of wood, making sure that it reaches the second piece of wood. 4. Once the pilot hole has been made, line another 1≤ finish nail with a drop of glue. 5. Drive this finish nail into the hole with a hammer, using a nail-set to sink the nail slightly beneath the wood’s surface. 6. Cover the hole with glue. 7. Proceed to the next joint, repeating steps 1 to 6 until all of the necessary pieces of wood have been joined to form the frame. 8. Once all of the pieces of wood have been joined, wipe off any excess glue and allow the joints to dry for a few hours. The above procedure mostly applies to the outermost pieces of a given frame structure. Once the outermost pieces of basswood have been joined, forming a two or three-dimensional frame, the inner pieces may be joined without recourse to the 90° corner-clamp. Simply mark the intended location in pencil on the frame, place the piece of wood at the indicating mark, and glue, drill, and join. Repeat for as many pieces as needed. 77

Figure 2.35A, B, C, D, and E Stages in joining basswood framestock to make a frame. (A) Gluing two pieces of wood together in a 90° corner-clamp. (B) Drilling a pilot hole with a nail. (C) Hammering a finish nail into the hole. (D) Sinking the nail slightly beneath the wood’s surface with a nail-set. (E) The finished joint. A

B

C

D

E

NOTES 1. The terms “sliding box-camera” and “folding-camera” have been adapted from descriptions of cameras given in Brian Coe, Cameras: From Daguerreotypes to Instant Pictures ([New York]: Crown Publishers, 1978), 20; and W. [Marcus] Sparling, Theory and Practice of the Photographic Art (1856; reprint, New York: Arno, 1973), 39–40.

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2. For the history and practice of pinhole photography, see Eric Renner, Pinhole Photography: Rediscovering a Historic Technique, 2nd ed. (Boston: Focal Press, 1999). 3. A general survey of the history and evolution of the camera obscura is to be found in John H. Hammond, The Camera Obscura: A Chronicle (Bristol [U.K.]: Adam Hilger, 1981). 4. Ibid., 96–98, 100–101. 5. Ibid., 162–163. 6. Information concerning Davy and Wedgwood can be found in R.B. Litchfield, Tom Wedgwood: The First Photographer (London: Duckworth, 1903). 7. For more on the camera used by Nicéphore Niépce, see Paul Jay and Michel Frizot, comps., Nicéphore Niépce, 2nd ed., Photo Poche 8 (Paris: Centre National de la Photographie, 1983), 117. Also see Michel Auer, The Illustrated History of the Camera from 1839 to the Present, trans. D.B. Tubbs (Boston: New York Graphic Society, 1975), 28–33. 8. A good description of Chevalier’s Grand Photographe is given in Eaton S. Lothrop, Jr. A Century of Cameras (Dobbs Ferry, N.Y.: Morgan & Morgan, 1973), 2. Also see Coe, Cameras, 22; and Auer, History of the Camera, 69. For the first published illustration, see the folding-plate located at the end of Charles Chevalier, Nouvelles instructions sur l’usage du daguerréotype (Paris: [self-published], 1841). Chevalier’s camera design remained essentially unchanged in subsequent publications. 9. For illustrations of 1850s-era photographic equipment, see Robert Hunt, A Manual of Photography (1853; reprint, New York: Arno, 1973), 198–204; and Sparling, Theory and Practice, 39–45. 10. For an illustration and description of the pocket camera obscura, see The Magazine of Science, vol. 4, no. 7 (May 14, 1842): 49–50. For Ottewill’s folding-camera, see Hunt, A Manual of Photography, 203, figs. 53 and 55; and Sparling, Theory and Practice, 42, figs. 42–43.

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3 The Lens This chapter addresses the construction of lenses for use with the film-holders and cameras presented in Chapters 1 and 2. It begins with a survey of essential lens configurations with related subjects like focal length, angle of view, f-stop, and aberrations being considered. Following this is a list of tools and materials needed to construct lenses, leading to the procedural steps for constructing four types of mid-nineteenth-century lenses: the singlet, or landscape lens; the symmetrical duplet, or periscopic lens; the asymmetrical duplet, or portrait lens; and the symmetrical triplet.1 Brief historical summaries for each lens are also provided. The lenses presented in this chapter have been chosen because they are easy to construct and do not require complicated mathematical equations or extremely precise engineering. They also offer reasonable approximations of certain mid-nineteenth-century photographic lens designs, and they demonstrate many of the optical problems challenging calotype-era photographers. While mostly conceived in relation to the negative and positive printing techniques described in this book, they may be used with modern film and paper emulsions. They may also be adapted for use with modern viewcameras by substituting lens boards that match the camera for the lens boards given here.

LENS CONFIGURATIONS Terminology surrounding the description of lenses differs significantly from generation to generation as well as from author to author. I will consider lenses using a basic approach, describing them as being simple, combined, or compound. A simple lens consists of an individual lens element, as, for example, a magnifying glass. A combined lens consists of two or more simple lens elements placed in contact with each other, forming a new combined lens element. Take apart a broken pair of binoculars, hold up one of the lens elements and view it from the side, and you will probably see a 81

combined lens element. A compound lens consists of two or more lens elements, either simple or combined, which are separated by an appreciable distance, usually in some sort of tube, or lens barrel. Most contemporary photographic lenses are examples of compound lenses.

Simple Lenses A simple lens may be generally considered in terms of its diameter, focal length, and shape.2 The diameter refers to the diameter of the focusing element itself, which is most easily determined by measuring the diameter of the lens with a ruler. The focal length refers to a hypothetical distance between the focusing element and a focused image, and can either be positive or negative. The shape ultimately determines whether the lens focal length is positive or negative, with positive focal length lenses being derived from bi-convex, planoconvex, and positive meniscus shapes, and negative focal length lenses being derived from bi-concave, plano-concave, and negative meniscus shapes (see Figure 3.1). Positive lenses magnify, rather than reduce. Hold a positive lens up to an object such as your hand, look through the lens, and you will see that the object appears visibly enlarged. Used by themselves, positive lenses are also capable of yielding projected images, thus fulfilling the most important requirement of a photographic lens. You can see this very easily for yourself. In the shade of a darkened room, hold a positive lens up to a white piece of paper. Direct the lens at daylight entering from a window, holding the paper behind the lens, and by varying the distance between the lens and the piece of paper, you will eventually see an inverted, focused image of the window projected upon the piece of paper. Move closer to the window and you will see that the distance between the lens and the focused image on the paper increases. Move away from the window and you will see that the distance decreases. In many ways, negative lenses are the polar opposite of positive lenses; they reduce rather than magnify. Hold a negative lens up to an object such as your hand, look through the lens, and you will see that the object appears visibly reduced. Unlike positive lenses, negative lenses are incapable of yielding projected images when used by themselves. That does not prevent them from playing a significant role in photography. For when they are used in combination with positive lenses, they have the power of altering positive lenses’ ability to magnify and produce images.

Combined Lenses A combined lens is a combination of two or more simple lenses placed in contact with each other to arrive at a new lens configuration.3 Like simple lenses, combined lenses are generally considered according to their diameter, focal length, and shape. Focal lengths are again either positive or negative, with positive combined lenses 82

Figure 3.1 Simple lens elements. Top row, left to right: bi-concave, plano-concave, negative meniscus. Bottom row, left to right: bi-convex, plano-convex, positive meniscus. Reprinted from D[ésiré] v[an] Monckhoven, Traité d’optique photographique (Paris, 1866), 52, fig. 17.

Figure 3.2 Combined lens elements. Top row, left to right: biconcave, plano-concave, and positive meniscus. Bottom row, left to right: bi-convex, plano-convex, and negative meniscus. Reprinted from D[ésiré] v[an] Monckhoven, Traité d’optique photographique (Paris, 1866), 94, fig. 39.

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being able to project images, and negative combined lenses being employed for their image-altering abilities. Once again, positive combined lenses come in three principal forms: bi-convex, planoconvex, and positive meniscus. This is also the case for negative combined lenses: bi-concave, plano-concave, and negative meniscus (see Figure 3.2). An important aspect of combined lenses is that combining one lens element with another will yield an entirely new focal length. This is useful to know particularly if you want to shorten or lengthen the focal length for any reason. A positive lens element added to another positive lens element will always be positive, with the combination resulting in a shortened focal length. Similarly, a negative lens element added to another negative lens element will always be negative, with the combination also resulting in a shortened focal length. But a positive lens element added to a negative lens element may either be positive or negative, according to whichever lens element has the shorter focal length, with the combination resulting in a lengthened positive or negative focal length. As it is useful to be able to predetermine the outcome of any such combination, the following equation has been established for a combined lens consisting of two lenses in contact: 1 f = 1 f1+ 1 f 2

(3.1)

Here f represents the resulting focal length of the lens combination, with f1 and f2 representing the respective focal lengths of two simple lenses in contact. For example, if you wanted to know the result of combining two simple bi-convex lenses, each with a focal length of 200 mm, you would add them together as follows to arrive at a combined focal length of 100 mm: 1/f = 1/200 + 1/200 1/f = 2/200 1/f = 1/100 f = 100 Provided that you already know the combined focal length of the two lenses and the focal length of one of the lenses, it is also possible to determine the focal length of a missing element. For example, if you combined a bi-convex lens with a focal length of 166 mm with a plano-concave lens of an unknown focal length to arrive at a combined focal length of 332 mm, you would use the general equation (3.1) as follows to arrive at a missing plano-concave focal length of -332 mm: 1/332 = 1/166 + 1/f2 1/332 = 2/332 + 1/f2 1/332 - 2/332 = 1/f2

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-1/332 = 1/f2 -332 = f2 For combined lenses with more than two elements in contact, the general equation (3.1) is written as follows: 1/f = 1/f1 + 1/f2 + 1/f3 . . . Apart from the new focal lengths that result, another reason for combining lenses is to eliminate focusing problems known as aberrations, which are described in further detail below. By combining lenses made of different types of glass with specified lens curvatures, these aberrations can either be diminished significantly or removed entirely. This is a complicated affair, however, involving the knowledge of trigonometry.4 Therefore, we will emphasize the role of limiting apertures in minimizing these aberrations, as they are within the scope and purpose of the present undertaking.

Compound Lenses A compound lens consists of two or more lens elements, either simple or combined, placed in an opposing arrangement along a common linear axis, or optical center, as in a lens barrel. The lens elements are separated by an appreciable distance, which affects the resulting focal length of the entire arrangement. Compound lenses may either be symmetric or asymmetric, depending on whether the opposing lens elements are the same. Like combined lenses, compound lenses can be difficult to calculate and make, involving a knowledge of trigonometry beyond the scope and purpose of the present undertaking.5 Rather, we will emphasize compound arrangements that require far less exacting standards of design and construction. Like combined lenses, it is necessary to add the focal lengths of the individual lens elements together in order to arrive at the focal length for a compound lens. Just about the only difference is that with compound lenses the distance separating the lens elements must also be taken into account. The following represents a modification of the general equation for two lenses in contact (3.1), in order to include the distance between the lens elements: 1 f = 1 f 1 + 1 f 2 - d f 1f 2 .

(3.2)

Here f represents the focal length of the compound lens, f1 and f2 the separated lens elements, either simple or combined, and d the distance between these elements. For example, if you had two positive meniscus lens elements, each with a focal length of 500 mm, and a separation of 100 mm between the lens elements, you would use

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the above equation as follows to arrive at a compound focal length of 278 mm: 1/f = 1/500 + 1/500 - 100/250,000 1/f = 5/2500 + 5/2500 - 1/2500 1/f = 9/2500 9f = 2500 f = 278

PHYSICAL PROPERTIES In addition to the different types of lenses, it is important to consider how much light a lens will allow to reach the image area, or film plane. This involves the interrelation of the distance the light has to travel, the size of the lens opening, and the number of glass surfaces involved. In photographic terms, this contributes to determining how much exposure to give the negative, and translates into the focal length, f-stop, and transmittance factor of a given lens. Different methods have been advanced for determining these variables, ranging from simple, approximating methods to complex, mathematical aims at precision.6 I will address the simpler methods, for all you really need to establish is a reasonable point of reference.

Focal Length The focal length generally refers to the distance between the lens and a focused image on the film plane. This distance varies according to the distance of the object being focused, and for this reason, a distant object on the horizon is usually chosen as a standard point of reference, its distance nominally being given as infinity. In using most positive lenses to focus upon an object on the horizon, measuring the distance between the lens element and the image formed at the center of the focusing screen is sufficient to form an approximation of the focal length of the lens, known more specifically in this case as the principal focus. With a steeply curved positive meniscus lens or a compound arrangement of lenses, however, a more precise method of determining the absolute focal length of the lens is needed, due to the thickness of the curved lens element or the distance separating the compound lens arrangement. In these cases, an easy method for determining the absolute focal length of a lens, known as Grubb’s method, can be applied as follows (see Figure 3.3):7 1. Place the camera on a leveled surface, such as a table top, with a large piece of white paper placed between the camera and the leveled surface. 2. Using a magic marker, draw a line along the vertical axis of the focusing screen. 3. With the lens and focusing screen installed in the camera, adjust the focus until the horizon line (see Figure 3.3, AB) 86

Figure 3.3 Diagram illustrating Grubb’s method for determining the absolute focal length of a lens. Reprinted from D[ésiré] v[an] Monckhoven, Traité d’optique photographique (Paris, 1866), 73, fig. 28.

4.

5.

6. 7. 8.

comes into focus. Note any identifying horizontal details present at the left and right limits of the focusing screen (see Figure 3.3, DE ), and with a ruler measure the distance that separates these details on the focusing section. Leaving the camera on the leveled surface, rotate the camera so that the line on the vertical axis of the focusing screen lines up with the horizontal detail that was formerly at the extreme left (see Figure 3.3, CD). Once this is achieved, mark a line in pencil on the paper, running along one of the sides of the camera (see Figure 3.3, cd ). Again leaving the camera on the leveled surface, rotate the camera so that the line on the vertical axis of the focusing screen lines up with the horizontal detail that was formerly at the extreme right (see Figure 3.3, CE ). Once this is achieved, mark a second line on the paper, running along the same side of the camera used in step 4 (see Figure 3.3, ce). Remove the camera from the paper and extend either of two lines as needed, forming an angle (see Figure 3.3, ecd ). Using a compass, bisect the angle just formed. Placing a square or a triangle against the bisecting line (see Figure 3.3, cf ), adjust the square until a distance 87

measuring exactly one-half the distance measured in step 3 is reached (see Figure 3.3, fg). 9. Mark a line there, extending it so that it reaches the angle formed in step 6 (see Figure 3.3, hg). This line should equal the line measured in step 3. 10. Measure the distance of the bisecting line drawn in step 7, from the apex of the angle to where it crosses the line drawn in step 9 (see Figure 3.3, cf ). This distance is the absolute focal length of the lens.

Angle of View The angle of view is best understood as the angle formed by the lens and opposing corners forming the diagonal of the format, with the lens focused at infinity.8 Finding the angle of view for a given lens and format combination is very easy. The following method, established by Clarence Woodman, is recommended: 1. Determine the diagonal of the format, either by measuring the two opposite corners or by applying the Pythagorean Theorem (see Chapter 1). For example, the diagonal of a 210 mm ¥ 270 mm rectangle is 342 mm. 2. Determine the quotient for the lens and format being used by dividing the lens focal length into the diagonal. For example, with a 250 mm focal length lens used with the 342 mm format diagonal, 342 is divided by 25 to arrive at 0.8047. 3. Taking the quotient from step 2, refer to Table 3.1 to determine the angle of view for the lens. For example, using the quotient 0.8047 from step 2, a 400 mm lens used with a 210 ¥ 270 mm format negative is found to have an angle of view measuring approximately 44°. Knowing the angle of view is helpful because it allows you to determine whether your lens is normal-angle, wide-field, wide-angle, or narrow-angle (often wrongly called telephoto). Taking the diagonal measurement of the format as the standard focal length for a lens with a normal angle of view, you divide the diagonal measurement into itself to arrive at 1, which translates to a normal angle of view measuring 53°. Strictly speaking, any lens having an angle of view less than 53° becomes narrow-angle and any lens with an angle of view greater than 53° becomes wide-field, with angles measuring 90° or greater being wide-angle.9 Referring to the format tables given in Chapter 1 (see Tables 1.2 to 1.4), you see that English midnineteenth-century singlet landscape lenses ranged from 46° to 51°, and were slightly narrow-angle, while their French counterparts were strictly 45°, which was slightly narrower. Determining the angle of view for mid-nineteenth-century duplet lenses is more complicated, however, because the lens manufacturers typically listed the focal length as measured from the rear focusing element rather than the 88

Table 3.1 Clarence Woodman’s Table for Determining the Angle of View (Found by Dividing the Diagonal of the Format by the Focal Length of the Lens) 0.282 = 16° 0.555 = 31° 0.849 = 46° 1.178 = 61° 1.56 = 76° 0.3 = 17° 0.573 = 32° 0.87 = 47° 1.2 = 62° 1.59 = 77° 0.317 = 18° 0.592 = 33° 0.89 = 48° 1.225 = 63° 1.62 = 78° 0.335 = 19° 0.611 = 34° 0.911 = 49° 1.25 = 64° 1.649 = 79° 0.353 = 20° 0.631 = 35° 0.933 = 50° 1.274 = 65° 1.678 = 80° 0.37 = 21° 0.65 = 36° 0.954 = 51° 1.3 = 66° 1.7 = 81° 0.389 = 22° 0.67 = 37° 0.975 = 52° 1.32 = 67° 1.739 = 82° 0.407 = 23° 0.689 = 38° 1 = 53° 1.36 = 68° 1.769 = 83° 0.425 = 24° 0.708 = 39° 1.02 = 54° 1.375 = 69° 1.8 = 84° 0.443 = 25° 0.728 = 40° 1.041 = 55° 1.4 = 70° 1.833 = 85° 0.462 = 26° 0.748 = 41° 1.063 = 56° 1.427 = 71° 1.865 = 86° 0.48 = 27° 0.768 = 42° 1.086 = 57° 1.45 = 72° 1.898 = 87° 0.5 = 28° 0.788 = 43° 1.108 = 58° 1.48 = 73° 1.931 = 88° 0.517 = 29° 0.808 = 44° 1.132 = 59° 1.5 = 74° 1.965 = 89° 0.536 = 30° 0.828 = 45° 1.155 = 60° 1.53 = 75° 2 = 90° Source: Adapted from Tho[ma]s Bolas and George E. Brown, The Lens: A Practical Guide to the Choice, Use, and Testing of Photographic Objectives (London: Dawbarn and Ward, 1902), 28.

actual focal length. Thus, from a cursory glance at the format tables given in Chapter 1, it would appear that English and French mid-nineteenth-century asymmetric duplet, or portrait lenses, were generally normal- to wide-field. The truth is that the absolute focal lengths were longer than stated, probably making them narrow-angle to normal-angle.10 Generally speaking, the potentiality for a lens to suffer from various aberrations increases as the angle of view increases. Therefore, in order to keep the aberrations to a minimum, it is advisable to construct a lens with a narrower angle of view whenever possible. Conversely, in order to emphasize certain aberrations, it would be advisable to construct a lens with a wider angle of view. The angle of view is to be distinguished from the field of view, which pertains to the angle formed between the lens and actual objects viewed on either the horizontal or vertical axis. Also related to the angle of view is the circle of definition, which pertains to the circular area in focus, as received upon the film plane. Ideally, the diameter of this area should be equal to or greater than the diagonal of the rectangle, but in the case of lenses exhibiting curvature of field (discussed below), this diameter may be significantly smaller than the diagonal of the format in question.11

Circle of Illumination The circle of illumination has to do with the inequality of light striking the film plane, as measured from the center of the image to the edge. Inequality in the amount of light is unavoidable due to 89

the increased distance that the light has to travel in order to reach the edge of the image relative to the center. With narrow-angle and normal-angle lenses, this inequality in illumination is generally so small as to pass unnoticed, but with wide-field and wide-angle lenses, it can result in a noticeable falling off of illumination that needs to be taken into consideration.12 Inequality in illumination has been calculated and is given here in Table 3.2. By halving the angle of view for a given lens, one obtains the angle of obliquity to the optical axis of that lens, which then translates into the loss of illumination to be anticipated for a particular angle of view. For example, if one wanted to determine the falling off of light for a lens with a normal angle of view, or 53°, one would divide 53 in half to obtain the angle of obliquity relative to the optical axis, or 26.5°. Looking at Table 3.2, this translates to an illumination of about 66 percent at the margins of the format, as opposed to 100 percent at the center, or a difference of about twothirds of a stop, which is not enough to be seriously noticeable on the print. Nevertheless, to take another example, with a lens with a wide angle of view measuring 90°, the resultant 45° angle of obliquity would mean a marginal illumination of 25 percent, or a difference of two stops relative to the center. This would represent a significant amount of darkening at the corners and edges of the print that would have to be accounted for as it would affect the aesthetic feel of the resulting photograph.

Aperture The aperture pertains to the volume of light being admitted into the lens. It is either limited by the diameter of the lens element itself or by the introduction of a stop, or diaphragm, which for our purposes will consist of a black piece of construction paper with a hole cut into it. Stops may be used with a lens in one of two ways. The first way consists of installing the stop at a distance in front of the focusing element, as, for example, in a singlet landscape lens. This has the effect of admitting light that is more parallel to the optical axis rather than oblique to it. The second way consists of installing Table 3.2 Angle of Obliquity

Illumination at Angles Oblique to the Optical Axis of the Lens Illumination at Focal Plane

Angle of Obliquity

Illumination at Focal Plane

Angle of Obliquity

Illumination at Focal Plane

0° 100% 20° 78% 40° 34% 5° 98% 25° 67% 45° 25% 10° 94% 30° 56% 50° 17% 15° 87% 35° 45% 55° 11% Source: Adapted from Tho[ma]s Bolas and George E. Brown, The Lens: A Practical Guide to the Choice, Use, and Testing of Photographic Objectives (London: Dawbarn and Ward, 1902), 31.

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the stop between opposing elements of a compound lens, as, for example, in a symmetrical duplet. This has the effect of reducing light to the optical center, which means that light may enter the lens from oblique angles in addition to the optical axis. Stops are invaluable aids in bringing objects into focus upon the film plane. By varying the size of the opening of the lens, they also allow for a precise determination of how much exposure to give the negative, relative to what is called the f-stop, or a ratio between the aperture of the lens and the focal length. In order to determine the f-stop, it is necessary to make a distinction between what is called actual aperture and effective aperture, for it is the diameter of the effective aperture that must be divided into the lens focal length to determine the f-stop.13 The actual aperture refers to the actual size of the aperture itself, which is easily determined by measuring its diameter with a ruler. With singlet landscape lenses and asymmetrical portrait lenses, in which the aperture is located in front of the lens, determining the actual aperture is all that is needed; the actual diameter is the same as the effective aperture. With a duplet or triplet lens, however, light is condensed in passing through the first lens element, prior to reaching the stop located between the opposing lens elements, and this needs to be taken into consideration. In such cases, the effective aperture can be easily determined using Steinheil’s method, which is given as follows: 1. In a darkened room, with a camera and focusing screen (see Chapters 1 and 2), open a window and focus the lens upon a very distant object at infinity (that is, the horizon). This object should be located at the exact center of the focusing screen. 2. Remove the focusing screen from the camera, take out the glass, and replace it with a black piece of card-stock with a small hole (for example, 1/8≤) cut into its exact center. 3. Closing the window and darkening the room entirely, hold an illuminated light bulb up to the hole in the card-stock, simultaneously holding the glass of the focusing screen up to the front of the lens. A projected, circular hole should now be visible upon it. 4. Measure the diameter of the projected hole. This is the effective aperture. 5. Divide this measurement into the focal length of the lens to determine the f-stop.

Transmittance Transmittance pertains to the amount of light entering a lens, viewed in relation to its absorption by the glass of the lens and its reflection by lens surfaces. This is to a large extent eliminated in

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modern lens elements by antireflection coatings, but with uncoated and uncorrected lenses, it still exists and should be taken into consideration prior to making the exposure, independent of the f-stop number. It also is a factor in the wet process film-holder presented in Chapter 1, in which the light must pass through the front and back surface of a sheet of glass prior to reaching the sensitized negative. Generally stated, every uncoated air-glass surface in a lens contributes to about a 5 percent reduction in light. An approximate transmittance of uncoated singlet, duplet, and triplet lenses is given in Table 3.3. From it, you can see that an uncoated landscape lens loses about 10 percent of light during exposure due to transmittance, which is hardly significant, but more importantly, that an uncoated symmetrical duplet or triplet lose anywhere from 19 percent to 27 percent, which is significant, since it equates to a loss of between a quarter and a half a stop over the entire image. Use of a glass plate in the film-holder contributes to an additional loss of about 10 percent.14

Aberrations In considering the physical properties of lenses, it is necessary to address certain inherent focusing problems, or aberrations, as they are called by optical engineers. The most significant of these are spherical aberration, coma, chromatic aberration, curvature of field, curvilinear distortion, and astigmatism. These either contribute to a lack of precision in the image or to a bending of lines that are normally perceived as straight. They are described more fully below, followed by simple solutions that have been proposed to reduce or eliminate them entirely. While aberrations are usually considered problems from the standpoint of optical precision, they may at times be used to great artistic effect (see Figure 3.4).

Spherical Aberration Spherical aberration is caused by light parallel to the optical axis being bent, or refracted, to a different point of focus by the edge of the lens rather than the center of the lens (see Figure 3.5). In photographic terms, this is characterized by an overall softening, combined with an aura-like emanation from focused subjects. Spherical aberration can be eliminated by using lens elements with different refracting indices, chosen for their ability to correct this discrepancy when Table 3.3 Type of Lens

Transmittance of Uncoated Lenses Number of Glass-Air Surfaces

Percentage of Transmittance

Singlet Lens 2 90% Duplet Lens 4 81% Triplet Lens 6 73% Source: Adapted from Allen R. Greenleaf, Photographic Optics (New York: Macmillan, 1950), 50.

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Figure 3.4 Julia-Margaret Cameron, “Vivien & Merlin.” This photograph, made with a lens having spherical aberration particularly noticeable in the highlights of the image, is a good example of putting so-called optical problems to great artistic effect. Reprinted from JuliaMargaret Cameron, Illustrations to Tennyson’s Idylls of the King, v.1, plate 4. Reproduced by permission of the Department of Printing and Graphic Arts, Houghton Library, Harvard College Library.

Figure 3.5 Spherical aberration. Light rays (r) entering the edge of the lens are brought to a shorter focus (f ’) than light rays (r’) entering closer to the optical axis of the lens (cc), which have a longer focus (f). Reprinted from D[ésiré] v[an] Monckhoven, Traité d’optique photographique (Paris, 1866), 80, fig. 29.

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Figure 3.6 Chromatic aberration. Left: white light passing through a prism and separating into component spectral colors. Right: the same effect as it applies to an uncorrected lens. Note that the violet-blue region to which the negative is attuned has a shorter focus than the green-yellow region to which the human eye is attuned. Reprinted from Tho[ma]s Bolas and George E. Brown, The Lens: A Practical Guide to the Choice, Use, and Testing of Photographic Objectives (London, 1902), 65, figs. 64 and 65.

used in combination. For our purposes, however, spherical aberration can most easily be reduced through the use of a small stop, and by using narrow-angle lenses, which are less spherically-shaped.15

Coma Coma is caused by light rays at angles oblique to the optical axis being bent, or refracted, in varying degrees by a lens, which prevents them from uniting at a common point of focus. It is characterized by a comet-like smearing in the margins of the image, whereby a concentrated point of light oriented towards the center of the film plane fans out into a diminishing broad band of light. Coma can be eliminated in much the same way as spherical aberration, to which it is related, by combining lens elements with different refracting indices and curvatures to correct for this tendency. For our purposes, coma can be most significantly reduced through the use of a small stop and a narrow-angle lens, which reduces the angle of obliquity to a minimum.16

Chromatic Aberration Chromatic aberration is a result of white light separating into its component spectral colors after passing through the lens (see Figure 3.6). In photographic terms, it is characterized by an overall lack of focus in the image due to the human eye being attuned to the green-yellow portion of the spectrum, whereas the light-sensitive emulsion is most sensitive to the violet-blue portion of the spectrum. For our purposes, chromatic aberration may most easily be eliminated by using combined lens elements that are said to be achromatic, meaning that two or more different types of glass have been used to correct the discrepancy between the human eye and the lightsensitive emulsion. As achromatic lens elements tend to be expensive, ordinary, uncorrected lenses may also be used as an economical alternative, provided that a slight focusing adjustment is made prior to making the exposure (see Figure 3.7).17 Adjusting the focus to compensate for chromatic aberration with uncorrected lenses is accomplished in the following way:18 1. Using the lens at full aperture, or without adding a stop, bring the primary subject into focus upon the focusing screen. 94

Figure 3.7 Correcting for chromatic aberration with an uncorrected lens. This photograph was made using a compound lens without a stop, consisting of two 75 mm diameter plano-convex lenses, with a focal length of 400 mm each, separated about 4≤ apart in a PVC tube. In focusing the center of the image, the apparent visual focus was first located upon the focusing screen. This was followed by a correcting adjustment, in which the camera back was brought forward to where the chemical focus was located. The result was that the image appeared visually out of focus during exposure, but after processing, the negative depicted the apparent visual focus prior to making the correction.

2. Measure the distance between the lens and focusing screen. 3. Once the distance has been determined, multiply it by 0.975 to arrive at the proper, adjusted distance for exposure. 4. Adjust either the lens or the camera until the lens and focusing screen are separated by the adjusted distance for exposure. The image will now appear slightly out of focus on the focusing screen. 5. Stop down on the lens as needed and make the exposure.

Curvature of Field Curvature of field is caused by light rays oblique to the optical axis of the lens being brought into focus at a different distance than light rays that are less oblique. This results in a curved or bowl-shaped image focus (see Figure 3.8). In photographic terms, curvature of field 95

Figure 3.8 Curvature of field. In this diagram, the straight line on the left results in a curved image focus on the right, after passing through the lens. Reprinted from W. [Marcus] Sparling, Theory and Practice of the Photographic Art (1853; reprint, New York, 1973), 34, fig. 21. [Sparling inaccurately described the illustration as exemplifying spherical aberration.]

Figure 3.9 The effect of curvature of field. This image, hand-tipped into a mid-nineteenth-century manual, is a good example of curvature of field as it appears in a photograph. Note that the center of the image is defined, whereas the margins are lacking in definition. By using a small stop, this problem would have been largely eliminated. Reprinted from D[ésiré] v[an] Monckhoven, Traité général de photographie (Paris, 1863), opposite 234.

is characterized either by a focus upon the center or by a focus upon the margins. In the former case, the margins lack definition, whereas in the latter case, the center lacks definition (see Figure 3.9). The result appears as a kind of secondary depth of field, wherein foreground objects in the margins appear defined in relation to distant objects in the center of the focal plane, prior to stopping down on the lens (see Figure 3.10). For our purposes, curvature of field is most effectively diminished by using meniscus lenses rather than bi-convex 96

Figure 3.10 Lowell’s Monument, Mount Auburn Cemetery, 1999. This photograph was doubleexposed using a landscape lens with different aperture settings to minimize but not eliminate curvature of field entirely. During the first exposure, the lens was left wide open for 15 seconds at f5.6, resulting in the soft-focus effects in the margins, particularly in the sky area. During the second exposure, the lens was stopped down to f16 for 2 minutes, resulting in a subtle definition in these same marginal areas, which was superimposed upon the first exposure to create an aura-like effect.

lenses and by increasing the distance between the stop and the lens, thus eliminating off-axial rays of light. It may also be diminished to a lesser extent by decreasing the size of the stop opening, or aperture, which serves to increase the depth of focus, extending the curved image focus to the image plane.19

Curvilinear Distortion Curvilinear distortion is caused by a variance in magnification, whereupon the edge of the lens magnifies the image in a disproportionate relation to the center. The result, in photographic terms, is that the straight lines of the resulting image either appear bowed-out, known as barrel distortion, or bowed-in, known as pincushion distortion (see Figures 3.11 to 3.13). Unlike the other aberrations, curvilinear distortion does not affect the apparent focus of the image. For 97

Figure 3.11 Diagram illustrating the effect of curvilinear distortion. From left to right: an undistorted image, barrel distortion, and pincushion distortion. Reprinted from D[ésiré] v[an] Monckhoven, Traité d’optique photographique (Paris, 1866), 114, figs. 55–57.

Figure 3.12 Frédéric Flachéron, San Giovanni in Laterano, Roma. This photograph, taken in the late 1840s, has a slight amount of barrel distortion. Hold the edge of a piece of paper up to one of the horizontal lines at the top of the photograph and you will see a slight bowing effect away from the center of the image. Reproduced by permission of the Department of Printing and Graphic Arts, Houghton Library, Harvard College Library.

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our purposes, it may be reduced to a significant extent by decreasing the distance between the stop and the lens, whereupon a compromise between curvature of field and curvilinear distortion must be reached, or by adding a second symmetrically opposed lens, which cancels out the distorting tendencies of the first lens.20

Astigmatism Astigmatism is caused by rays of light entering the lens at oblique angles to the optical axis being refracted in two different ways: one travelling along a plane which crosses a lens diameter in such a way that the refracted rays are symmetrically diverted to

a single focus, and the other travelling along a plane that crosses another lens diameter in an asymmetric way, resulting in the refracted rays being brought to another focus. In photographic terms, it is characterized by two sliding points of focus in the margin of the focal plane, which can never be united to form a single focus. Astigmatism can be corrected by combining lenses with different indices of refraction. For our purposes, it may be reduced through the use of a small stop and narrow-angle lenses.21

Figure 3.13 Naval Monument, Mount Auburn Cemetery, 1999. This photograph, made with a landscape lens stopped down to f32 in combination with a 49° angle of view, has a fair amount of barrel distortion, as seen on the right-hand side of the picture frame.

TOOLS NEEDED Most of the tools needed to construct lenses are quite common, and can be obtained from most hardware and art-supply stores. These are listed below, and require little additional information:

• A metal straight-edge, with millimeter and 1/16≤ markings • A metal square or plastic, right-angle triangle 99

• • • •

A pencil A miter box, with saw for cutting PVC A no. 1 X-acto® knife, with no. 11 blades A circle template, marked in metric sizes and fractions of an inch (for example, 3–28 mm and 1/8≤–1≤) • A compass for drawing circles (the cheap ones work fine) • A utility knife with blades • A caulk gun

MATERIALS NEEDED Most of the materials needed to construct lenses are also quite common and can be obtained from hardware and art-supply stores. Luan, a thin plywood used in covering hollow-core doors, can be obtained from a lumberyard. Sources for the optical lens elements are listed in Appendix: Sources of Supplies. The materials needed are as follows:

• PVC piping, with inner diameters ranging from 1-1/2≤ to 4≤ • A number of sheets of acid-free black construction paper • • • • • • • • • • • • • • •

(hold the paper up to a light to make sure it is free from pinholes) One or two sheets of black foam-core (3/8≤ and 1/2≤ thick, with black foam interior) A small sheet of single-strength window pane glass Lens cleaning tissue A small bottle of lens cleaning solution Acid-free black masking tape, 2≤ wide A sheet of Luan“ plywood (usually sold in 4¢ ¥ 8¢ sheets, although these can be scraps left over from Chapters 1 and 2) Black vinyl adhesive caulk (Phenoseal“ is recommended) Two strips of 2≤ ¥ 12≤ brass shim-stock A 5≤ diameter hose clamp 1/16≤ to 1/8≤ thick, dense black foam (sold in 8≤ ¥ 10≤ and 11≤ ¥ 14≤ sheets) A variety of optical lens elements Flat black enamel paint (Krylon“ ultra flat black is especially recommended) 1-1/2≤ hog-hair or synthetic bristle brush Turpentine Contact cement (can be used to cement lens elements and PVC)

THE SINGLET, OR LANDSCAPE LENS This section is devoted to the simplest of all lens designs, the landscape lens. This lens consists of either a plano-convex or a positive meniscus lens used in combination with a stop. Because the lens produces a curved field, it is generally used with a fairly small stop, 100

f16–f32, which necessitates long exposure times. When one positions the stop away from the lens, the field is significantly flattened, making it suitable for very large format negatives depicting unmoving subjects, like landscapes. Curvilinear distortion is more pronounced when the stop is away from the lens, but, with a narrow angle of view, this is kept to a minimum. Normally, the stop is placed in front of the lens, at a distance measuring 1/5 to 1/7 of the focal length.22

Historical Background The landscape lens was the first lens used for photographic purposes, dating to the 1820s and Nicéphore Niépce’s experiments with the heliographic process. At the time, the lens consisted of a simple, uncorrected positive meniscus lens element, with the concave surface being oriented towards the subject. Used with a stop placed at a distance measuring approximately 1/5 of the focal length in front of the lens, the resulting circle of definition measured 1/4 of the focal length with the lens stopped down to f30. Due to the lack of correction for chromatic aberration, focusing then had to be adjusted to compensate for the spectral difference between the visual focus and the focus of the light-sensitive surfaces. The lens was essentially an extension of the type used by Giovanni Battista della Porta in the sixteenth century, the shape of the lens having been modified from planoconvex to positive meniscus by William Hyde Wollaston in 1812, in combination with moving the stop away from the lens.23 Upon Louis Jacques Mandé Daguerre’s introduction of photography to the general public in 1839, it was understood that an achromatic lens was needed to correct for the discrepancy between the visual focus and what was then termed the chemical, or actinic, focus. Returning to the plano-convex shape, Charles Chevalier arrived at an achromatic combination in which the flat side faced the subject being viewed (see Figure 3.14). Like the Wollaston meniscus, the stop was placed in front of the lens, at a distance measuring 1/5 of the focal length, with the resulting circle of definition measuring 1/2 of the focal length when used at f30. The maximum aperture used was f15. The plano-convex shape was subsequently replaced by an achromatic positive meniscus shape that flattened the field even further.24 By the late 1850s and early 1860s, new types of achromatic landscape lenses evolved. These either reversed the order of the two types of glass being used or combined three simple lens elements rather than two in order to widen the angle of view. These were designated new form lenses so as to distinguish them from the earlier, old form lenses (see Figure 3.15).25

Preliminary Considerations Concerning Construction In making our landscape lens, we will follow the old form landscape lenses. This is partly because they were the landscape lenses 101

Figure 3.14 A landscape lens arrangement, circa 1839. Note the plano-convex element (AC) used in combination with a stop (B). Reprinted from D[ésiré] v[an] Monckhoven, Traité d’optique photographique (Paris, 1866), plate 1, fig. 3.

Figure 3.15 Old and new form landscape lenses. By the 1860s, singlet, achromatic lenses had evolved from the original, plano-convex shape with the softer flint glass in front, to a positive meniscus shape with the harder crown glass in front. This helped to protect the lens and flatten the field. Reprinted from Charles Fabre, Traité encyclopédique de photographie (Paris, 1889), v.1, 65, figs. 30–32.

used during the calotype era, and partly because they utilize the lens forms most readily available from optical suppliers today. Any of the following four types of lens element may be used: uncorrected positive meniscus, uncorrected plano-convex, achromatic positive meniscus, and achromatic plano-convex. Of the four, the uncorrected positive meniscus represents the flattest field for the cheapest price, as long as you remember to make the necessary focusing adjustment prior to exposure to account for chromatic aberration.

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Note: In contrast with the procedural steps listed in the other chapters of this book, with lens construction it has been deemed more beneficial to list an idealized series of procedural steps, since no exact lens specification can be expected to be obtainable on the market at any time. The following construction sequence is intended to serve as an example of the procedure to be followed in making a landscape lens. Exact dimensions, as given in the example, will need to be adjusted to match the lens element and format you are using. It is recommended that you follow certain guidelines in making landscape lenses. The following have in part been adapted from Désiré van Monckhoven, who laid out a similar set of guidelines in 1866:26

• The angle of view should be slightly narrow-angle, or approximately 45°. This allows us to determine the focal length for the format in question by dividing the diagonal of the format (see Tables 1.6 and 1.7) by the quotient for a 45° angle of view (see Table 3.1). Thus, for a 6-1/2≤ ¥ 8-1/2≤ format negative, the diagonal measuring 272 mm would be divided by 0.828 to arrive at an approximate focal length of 329 mm. In the same way, for a 210 mm ¥ 270 mm format negative, the diagonal measuring 342 mm would be divided by 0.828 to arrive at an approximate focal length of 413 mm. • The diameter of the lens element should measure approximately 1/5 to 1/7 of its focal length. Thus, for a 329 mm focal length lens used with a 6-1/2≤ ¥ 8-1/2≤ format negative, lens diameter should range between 47 mm and 66 mm. Similarly, for a 413 mm lens used with a 210 mm ¥ 270 mm format negative, lens diameter should range between 59 mm and 83 mm. • The stop should be placed in front of the lens element at a distance measuring approximately 1/6 to 1/7 of the focal length. Thus, for a 329 mm focal length lens used with an 6-1/2≤ ¥ 8-1/2≤ format negative, the stop should be located between 47 mm and 55 mm in front of the lens. Similarly, for a 413 mm lens used with a 210 mm ¥ 270 mm format negative, the stop should be located between 59 mm and 69 mm. This is to ensure the flattest field possible with the least amount of curvilinear distortion. The stop may be brought closer than this to reduce the curvilinear distortion at the cost of curvature of field. Moving the stop any further away than this runs the risk of vignetting the image. • For the best possible definition, the lens should be stopped down between f16 and f32 in making the exposure. Thus, for a 329 mm focal length lens used with a 6-1/2≤ ¥ 8-1/2≤ format negative, three separate stops are to be made, one with a 20 mm diameter hole cut into it for f16, another with a 15 mm hole cut into it for f22, and another with a 10 mm hole cut into it for f32. Similarly, for a 413 mm lens used

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with a 210 mm ¥ 270 mm format negative, three separate stops are to be made, one with a 26 mm hole cut into it for f16, another with a 19 mm hole cut into it for f22, and another with a 13 mm hole cut into it for f32. Another standard was put forward by an early photographic optician named Buron. He recommended that the focal length remain twice the length of the longer dimension of the plate format, in combination with a lens diameter or aperture measuring 1/7 of its focal length. This resulted in an extremely narrow 28° angle of view.27

Construction Procedure: Landscape Lens Listed below are the procedural steps for constructing a singlet landscape lens using an achromatic, 58 mm plano-convex lens element with a 362 mm focal length and a PVC lens barrel with a 3≤ inner diameter. The lens is to be used with a 6-1/2≤ ¥ 8-1/2≤ wholeplate negative. Refer to the diagrams (see Figures 3.16 to 3.19) for the procedural steps listed below: 1. Using a saw and miter box, cut a 2-1/8≤ section of PVC and a 1-1/4≤ section of PVC. These are to serve as the lens barrel. 2. In the same manner, cut a 1-9/16≤ section of PVC and three 3/8≤ sections of PVC. These are to serve as retaining rings for the lens and stop. 3. Taking the sections of PVC from step 2 remove a small portion of the O-shaped section with a handsaw so as to make them C-shaped. This is most easily achieved by viewing each O-shaped section as a clock face, whereupon the two saw cuts are made between 4 o’clock and 5 o’clock and 7 o’clock and 8 o’clock. 4. Check the fit of the C-shaped sections by sliding them into the two O-shaped sections from step 1. 5. Remove the C-shaped sections from the O-shaped sections and with a utility knife trim off any excess plastic remaining on the edges of the PVC. 6. In an area with adequate ventilation, spray paint all of the pieces of PVC flat black. Hold the can of spray paint at a distance of about 1 foot away so as to avoid drip marks. Allow to dry. 7. Turn the pieces over and spray paint the remaining unpainted surfaces. Allow to dry. 8. Taking a sheet of black construction paper, cut a piece measuring 4≤ ¥ 4≤. Find the center by drawing diagonal lines between corners. Then place a compass at the center and mark a circle with a radius of 1-1/2≤. Using a circle template, mark an 11 mm circle sharing a common center with the larger one. 104

3 1≤ 2

58mm 2≤

2≤

58mm

11mm

3≤ 8

3≤ 16

3≤ 8

9≤ 1 16

1≤ 2

(foam-core)

3 1≤ 2

2 1≤ 2

3≤

The stop is located here.

3≤

3≤ 8

(foam-core)

1 1≤ 4

2 1≤ 8 3 3≤ 8

9. Place the paper on a sheet of plate glass and, using an Xacto knife, cut along the two circles. Cut the circles by turning the paper on the glass, holding the knife in a vertical, stationary position, rather than dragging the knife across the paper. The circular formation that results is the stop. 10. Taking a sheet of 1/2≤ black foam-core, cut a piece measuring 4≤ ¥ 4≤. Find the center by drawing diagonal lines between the corners. Then place a compass at the center and mark a circle with a radius of 29 mm. Mark a second circle sharing the same center with a radius of 1-1/2≤. 11. Place the foam-core on a cutting surface and begin cutting the inner circle with an X-acto knife. Make sure that the blade remains in a vertical, upright position when the cuts are made, and do not try to cut through all of the foam-core at once. Rather, cut it so that a series of dotted marks become visible on the backside. Once the

Figure 3.16 362 mm focal length, achromatic plano-convex landscape lens, stopped down to f32. Front and side views.

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A

B

C

D

E

F

Figure 3.17A, B, C, D, E, and F Making the C-shaped retaining rings. (A) Cutting the PVC using a miter saw. (B) A 1/2≤ section. (C) Removing part of the section with a razor saw so as to make it C-shaped. (D) The C-shaped ring. (E) Installing the C-ring into a section of PVC. (F) The C-ring in place.

A

B

C

D

E

F

Figure 3.18A, B, C, D, E, and F Installing a lens element into a sheet of black foam-core. (A) A 4≤ ¥ 4≤ piece with diagonals crossed to find the center. (B) Marking the circumference of the lens barrel and lens element with a compass. (C) Cutting the circles with an X-acto knife. (D) The O-shaped piece of foam-core. (E) Sliding the lens into the O-shaped piece of foam-core. (F) The lens element taped in place.

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A

D

12. 13.

14. 15. 16.

17.

B

C

E

Figure 3.19A, B, C, D, and E Making a stop from black construction paper. (A) A 4≤ ¥ 4≤ piece, with diagonals crossed to find the center. (B) Marking the circumference of the lens barrel with a compass. (C) Marking the circumference of the stop with a circle template. (D) Cutting the circles with an X-acto knife and a sheet of glass. (E) The finished stop.

dotted outline of the circle is formed, turn the foam-core over and finish cutting by connecting the dotted marks with the knife. This ensures a more even cut. Repeat step 11, cutting the larger circle. The resulting Oshaped piece of foam-core is to hold the lens element in place. Using lens tissue, slide the lens element into the hole cut into the foam-core so that the flat side of the lens element is flush with one side of the foam core. The fit should be a little bit snug rather than loose. Remove any fingerprints as needed with lens cleaning tissue, using a drop of lens cleaning solution if need be. Repeat steps 10 through 12, forming an O-shaped support for the stop. This time, however, use 3/16≤ wide foam-core, and mark out an inner circle with a radius of 1≤. Taking one of the 3/8≤ C-shaped rings from step 2, slide it into one end of the 2-1/8≤ piece from step 1. Adjust as needed so that it is flush with the end of the 2-1/8≤ piece. Taking the lens element and O-shaped piece of foam-core from step 13, slide it into the tube and C-ring from step 15 so the foam-core with the convex side of the lens element is resting against the C-ring. Taking the 1-9/16≤ C-shaped ring from step 2, slide it into the remaining part of the 2-1/8≤ piece, until it is pressed against the foam-core holding the lens element. About 5/16≤ should remain above the 2-1/8≤ tube afterwards. Blow away any loose paint that has fallen onto the lens element. 107

18. Taking another of the 3/8≤ C-shaped rings from step 2, slide it into one end of the 1-1/4≤ section from step 1. Adjust as needed so that it is flush with the end. 19. Taking the black construction paper forming the stop from step 9, slide it into the 1-1/4≤ section so that it is resting against the C-shaped ring installed in step 18. Then slide the O-shaped supporting piece of foam-core from step 12 on top of the stop, followed by the remaining 3/8≤ C-shaped ring from step 2. There should now be approximately 5/16≤ remaining in the 1-1/4≤ section. 20. Connect the 1-1/4≤ section to the 2-1/8≤ section, forming the complete lens barrel. The lens should be located at one end of the barrel and the stop at the other end of the barrel. The lens is now complete. The lens barrel is cut into two sections in order to facilitate the changing of f-stops, which in the construction example has a diameter of 11 mm, or f32. In this way, two additional 1-1/4≤ sections can also be made, one with a stop diameter measuring 16 mm, for f22, and the other with a stop diameter measuring 23 mm, for f16. Stops can be easily changed by switching 1-1/4≤ sections at the front of the lens (see Figures 3.20 and 3.21).

THE SYMMETRICAL DUPLET, OR PERISCOPIC LENS This section is devoted to a compound lens design known as the symmetrical duplet lens. The lens consists of two identical landscape lenses that are placed face to face with a stop in between the lens elements (see Figures 3.22 and 3.23). This allows for a wider angle of view and eliminates curvilinear distortion and coma. These benefits are offset by a significant amount of curvature of field being introduced, which often means that a very small stop is needed to rectify this, often on the order of f45 to f64. An alternative approach is to construct a symmetrical duplet lens with a very narrow angle of view. This results in a softer diffused-focus lens that can be used full aperture for pictorialist-type effects.28

Historical Background The first use of a symmetrical duplet lens for photographic purposes dates to 1841 when Thomas Davidson placed two Chevalier achromatic landscape lenses face to face. Similarly, in 1844, G.S. Crundell mounted two uncorrected Wollaston meniscus lenses around a central stop. Presumably, these were attempts to correct for curvilinear distortion or to use the lens at full aperture.29 Between the late 1850s to mid-1860s, a number of symmetrical lenses were introduced to widen the angle of view. One of the strangest 108

Figure 3.20A and B A completed landscape lens with removable stop. (A) The lens with stopped removed. (B) The stop in place.

A

B

Figure 3.21 A landscape lens with additional stops. These allow the lens to be used at f16 or f22, in addition to f32.

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Figure 3.22 Two uncorrected lenses arranged around a central stop. Reprinted from Tho[ma]s Bolas and George E. Brown, The Lens: A Practical Guide to the Choice, Use, and Testing of Photographic Objectives (London, 1902), 74, fig. 78.

Figure 3.23 Two achromatic lenses arranged around a central stop. Reprinted from Tho[ma]s Bolas and George E. Brown, The Lens: A Practical Guide to the Choice, Use, and Testing of Photographic Objectives (London, 1902), 79, fig. 88.

of these was a ball lens designed by Thomas Sutton. It consisted of two extremely curved positive meniscus lenses, with water rather than air occupying the space between the elements. Viewed along the horizontal axis of the format, and used with a curved film plane, it had a 100° angle of view. In 1865, Adolph Steinheil introduced a lens known as the Periskop, which consisted of two positive meniscus lens elements arranged around a central stop (see Figure 3.24). Very simple in design, it represented a return to Crundell’s original arrangement.30 At the debut of the twentieth century, the Wollensak Optical Company introduced two soft-focus variants of Steinheil’s Periskop, which were designed to be used at full aperture, rather than stopped down, for pictorialist-style portrait work.31

Preliminary Considerations Regarding Construction Symmetrical duplets may be assembled from any identical pair of lenses, corrected or uncorrected, which are preferably positive

110

A

B

meniscus in shape. The distance between the lens elements can vary considerably, provided that the stop is placed exactly in between, and that the distance separating the elements is not so great as to introduce vignetting. As was the case with the landscape lens, increasing the distance between the lenses and the central stop reduces curvature of field, and results in a narrower angle of view, whereas decreasing the distance augments curvature of field, and results in a wider angle of view. Stopped down considerably, an angle of view ranging from 53° to 90° is possible, combined with little or no distortion. Used full aperture, with the lens elements at a significant distance apart (that is, with each element placed about 1/5 to 1/7 of its focal length away from the stop), the circle of definition ranges about 15° to 20°, making it extremely narrow-angle. This can be useful for soft-focus, pictorialist effects with the negative trimmed down to a smaller format. Note: In contrast with the procedural steps listed in the other chapters of this book, with lens construction it has been deemed more

Figure 3.24A and B Two nineteenth-century views of Steinheil’s Periskop. (A) Reprinted from D[ésiré] v[an] Monckhoven, Traité d’optique photographique (Paris, 1866), 144, fig. 67 (B) Reprinted from Charles Fabre, Traité encyclopédique de photographie (Paris, 1889), v.1, 82, fig.42.

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Table 3.4

Dimensions of Steinheil’s Periskop

Diameter of the Lens Elements

Absolute Focal Length

Circle of Definition at f64

8.9 mm 74 mm 122 mm 11.2 mm 89 mm 176 mm 18 mm 144 mm 270 mm 22.5 mm 176 mm 352 mm 33.8 mm 352 mm 568 mm 47.4 mm 406 mm 812 mm 56.4 mm 587 mm 812 mm Source: D[ésiré] v[an] Monckhoven, Traité d’optique photographique (Paris: Victor Masson, 1866), 145.

beneficial to list an idealized series of procedural steps since no exact lens specification can be expected to be obtainable on the market at any time. The following construction sequence is intended to serve as an example of the procedure to be followed in making the symmetrical duplet lens known as Steinheil’s Periskop. Exact dimensions, as given in the example, will need to be adjusted to match the lens element and format you are using. This being the case, it is recommended that you follow certain guidelines in making the lens. The following have been adapted from Monckhoven’s 1866 description of the lens,32 to which a table listing varying dimensions of lens diameter, focal length, and circle of definition has been appended (see Table 3.4):

• The angle of view should be normal- to wide-angle, ranging anywhere from 53° to 90° depending on the curvature of the lenses being used (see Table 3.1). Thus, for a wide field of view measuring 60° combined with a 6-1/2≤ ¥ 8-1/2≤ format negative, the diagonal measuring 272 mm would be divided by 1.155 in order to arrive at an absolute focal length of 235 mm. In the same way, the diagonal of a 210 mm ¥ 270 mm format negative measuring 342 mm would be divided by 1.155 to arrive at an absolute focal length of 296 mm. The focal length of the individual lens components may be determined using equation 3.2, but as the distance which separates them is rather small in this case, it may generally be said to be about twice the absolute focal length. • Two identical, positive meniscus lenses should be used. They are uncorrected for chromatic aberration, necessitating a focusing adjustment. • The diameters of the lens elements should measure approximately 1/8 to 1/10 of the absolute focal length. For a 235 mm focal length lens used with an 8-1/2≤ ¥ 6-1/2≤ format negative, the lens diameter should range between 24 mm and 29 mm. Similarly, for a 296 mm focal length lens 112

used with a 210 mm ¥ 270 mm format negative, lens diameter should range between 30 mm and 37 mm. • The distance between the lens elements should equal the diameter of the lens elements, with a stop placed in between. If a flatter field is desired, the distance may be increased slightly, up to about 1.5 times the diameter, with vignetting occurring rapidly due to the relatively small diameters involved. • For the best possible definition, the lens should be stopped down between f45 to f64 in making the exposure. Larger apertures may be used as well, but they will show significant curvature of field and astigmatism. Use the method for determining the effective aperture outlined above to determine the actual diameter of the stops to be used.

Construction Procedure: Steinheil’s Periskop Listed below are the procedural steps for constructing a symmetrical duplet lens resembling Steinheil’s Periskop. It utilizes two uncorrected 28 mm positive meniscus lenses, each of them having a 500 mm focal length. The lens elements are spaced 28 mm apart in a PVC lens barrel with a 1-1/2≤ inner diameter, resulting in an actual focal length of 257 mm. Used with an 8-1/2≤ ¥ 6-1/2≤ format negative, it is approximately normal-angle, with a 56° angle of view. Refer to the diagram (see Figure 3.25) in constructing the lens as follows: 1. Using a saw and miter box, cut a 7/8≤ section of PVC and a 5/8≤ section of PVC. These are to serve as the lens barrel. 2. In the same manner, cut two 3/8≤ sections of PVC and two 3/16≤ sections of PVC. These are to serve as retaining rings for the lens. 3. Taking the sections of PVC from step 2, remove a small portion of the O-shaped section with a handsaw so as to make them C-shaped (see Figure 3.17). This is most easily achieved by viewing each O-shaped section as a clock face, whereupon the two saw cuts are made between 4 o’clock and 5 o’clock and 7 o’clock and 8 o’clock. 4. Check the fit of the C-shaped sections by sliding them into the two O-shaped sections from step 1. 5. Remove the C-shaped sections from the O-shaped sections and trim off any excess plastic remaining on the edges of the PVC with a utility knife. 6. In an area with adequate ventilation, spray paint all of the pieces flat black. Hold the can of spray paint at a distance of about one foot away so as to avoid drip marks. Allow to dry. 7. Turn the pieces over and spray paint the remaining unpainted surfaces. Allow to dry. 113

The stop is located here.

Figure 3.25 257 mm focal length, symmetrical duplet lens. Front and side views. 7"

18

1"

12

3 " 3" 16 16

3"

3"

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8

(foam-core)

7"

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8. Taking a sheet of black construction paper, cut a piece measuring 2≤ ¥ 2≤ (see Figure 3.19). Find the center by drawing diagonal lines between corners. Then place a compass at the center and mark a circle with a radius of 3/4≤. Using a circle template, mark a circle with a 4 mm diameter sharing a common center with the larger one. 9. Place the paper on a sheet of plate glass and, using an Xacto knife, cut along the two circles. Cut the circles by turning the paper on the glass, holding the knife in a vertical, stationary position rather than dragging the knife across the paper. The circular formation which results is the stop. 10. Taking a sheet of 3/16≤ black foam-core, cut two pieces measuring 2≤ ¥ 2≤ (see Figure 3.18). Find the center of each by drawing diagonal lines between the corners. Then place a compass at the center of each piece and mark a circle with a radius of 14 mm. Mark a second circle sharing the same center with a radius of 3/4≤. 11. Place one of the pieces of foam-core on a cutting surface and begin cutting the inner circle of one of them with an X-acto knife. Make sure that the blade remains in a vertical, upright position when the cuts are made, and do not try to cut through all of the foam-core at once. Rather, cut it so that a series of dotted marks become visible on

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12. 13. 14.

15. 16. 17.

18.

19.

20. 21.

the backside. Once the dotted outline of the circle is formed, turn the foam-core over and finish cutting by connecting the dotted marks with the knife. This ensures a more even cut. Repeat step 11, cutting the larger circle. The resulting Oshaped piece of foam-core is to hold one of the lens elements in place. Repeat steps 11 and 12 for the other piece of foam-core. This is to hold the other lens element in place. Using lens tissue, slide one of the lens elements into the hole cut into one of the pieces of foam-core so that the convex side of the lens element is flush with one side of the foam-core. The fit should be a little bit snug rather than loose. Remove any fingerprints as needed with lens cleaning tissue, using a drop of lens cleaning solution if need be. Repeat step 14, installing the other lens element into the remaining piece of foam-core. Taking one of the 3/16≤ C-shaped rings from step 2, slide it into one end of the 7/8≤ piece from step 1. Adjust as needed so that it is flush with the end of 7/8≤ piece. Taking the lens element and O-shaped piece of foam-core from step 14, slide it into the tube and C-ring from step 16 so the foam-core with the convex side of the lens element is resting against the C-ring. Taking one of the 3/8≤ C-shaped rings from step 2, slide it into the remaining part of the 7/8≤ section, until it is pressed against the foam-core holding the lens element. About 1/8≤ should remain below the end of the 7/8≤ tube afterwards. Blow away any loose paint that has fallen onto the lens element. Repeat steps 16 through 18, using the 5/8≤ section and the remaining 3/16≤ and 3/8≤ C-shaped rings. About 1/8≤ of the 3/8≤ C-shaped ring should be above the end of the 5/8≤ section afterwards. Taking the black construction paper forming the stop from step 9, slide it into the 7/8≤ section so that it is resting against the C-shaped ring installed in step 18. Connect the 5/8≤ section to the 7/8≤ section, forming the complete lens barrel. The convex sides of both lens elements should be facing outwards with the concave sides facing each other and the stop exactly in between. The lens is now complete.

The lens barrel is cut into two sections in order to facilitate the changing of f-stops, which in the construction example has a diameter of 4 mm, or f64. In this way, two additional stops may be made from black construction paper, one with a hole diameter measuring 6 mm, or f45, and the other with a hole diameter measuring 8 mm,

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Figure 3.26 Two ways of using a Petzval Portrait Lens. The topmost illustration shows the lens being used the normal way, at full aperture, resulting in a centralized focus and unequal illumination at the edge. The lower illustration shows the lens being reversed to flatten the field and equalize the illumination, with the stop located in front. Reprinted from Tho[ma]s Bolas and George E. Brown, The Lens: A Practical Guide to the Choice, Use, and Testing of Photographic Objectives (London, 1902), 92, fig. 104.

or f32. Stops are easily changed by removing the 5/8≤ section at the front of the lens and changing the pieces of construction paper in the middle.

THE ASYMMETRICAL DUPLET, OR PORTRAIT LENS Apart from the symmetrical duplet configuration given above, it is also relatively easy to arrive at asymmetrical duplet configurations. This puts us in a category of lens design called “portrait lenses” or “double lenses” in the mid-nineteenth century. We will briefly consider two of these—the Petzval Portrait Lens and the Chevalier Photographe à verres combinés—before adopting the simpler method suggested by the Chevalier example.

Historical Background Based on the number of lenses sold in the 1840s and 1850s, the foremost among asymmetrical duplet lenses was the Petzval Portrait Lens, which, in its original configuration, consisted of an achromatized plano-convex lens in front and a separated, negative meniscus and bi-convex combination in the rear (see Figure 3.26). Upon its initial introduction in 1840, the Petzval Portrait Lens remained uncorrected for chromatic aberration, and the stop was located in front of the lens. Soon thereafter, an improved version was introduced that was completely achromatized along the optical axis. Because the lens suffered from astigmatism and curvilinear distortion, its use in 116

viewing landscape or architectural subjects was fairly limited. Apart from these shortcomings, it was greatly admired as a portrait lens because it could be used at full aperture, thus reducing exposure times. Another benefit was that it tended to emphasize the sitter at the center of the image, minimizing the background at the edge of the frame. In the mid-1850s, the stop was relocated from the front to the middle of the lens, between the front and back combinations. This helped to overcome curvilinear distortion to some extent. The aperture of the lens ranged from f4 to f25, with the circle of definition being approximately 15° at f4, 28° at f10, and 53° at f25.33 Given the relative complexity of the separated rear lens component, the Petzval Portrait Lens remains beyond our scope and purpose. Therefore, it may be consoling to bear in mind that no matter how popular it was, its circle of definition remained extremely narrow-angle at full aperture due to curvature of field. It was also criticized for its tendency to lose illumination at the edges of the picture frame (see Figure 3.27). Such shortcomings may be summed up in the words of Thomas Sutton, a mid-nineteenth-century British photographer living on the island of Jersey:

Figure 3.27 Charles Nègre, “Ramoneurs en marche,” c. 1851. This photograph is a good illustration of the centralized focus and loss of illumination attributed to portrait lenses. The size of the print, 152 mm ¥ 198 mm, or slightly under wholeplate, exhibits a smaller circle of definition extending to quarter-plate size. Reproduced by permission of the National Gallery of Canada, Ottawa.

A [Petzval] portrait lens is only intended to be used for subjects which must be taken quickly, or instantaneously. It does not give so

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flat a field as a view-lens [landscape lens]; nor does it give equality of illumination; nor can objects at different distances be all brought into good focus; nor does it include a wide angular field; nor does it give images free from distortion. In short, everything is sacrificed to the centre of the picture, and the lens should only be used when no other will answer for the purpose.34

Sutton proposed the following method for improving the lens when used at full aperture: Reverse the [Petzval] portrait lens; that is, turn it with the posterior lens to the objects, and let the other lens, which is a view lens, be made larger than usual. Then place a stop immediately in contact with the lens that is presented to the objects . . . [T]his will give a much flatter field than the portrait lens used in the ordinary way, and the picture will be more uniformly covered with good definition, and more equally illuminated, although possibly it may not be quite so good as before in the centre.35

What is interesting about Sutton’s remarks is that he appears to have modified the Petzval lens in accordance with another portrait lens design used during the mid-nineteenth century. This was Charles Chevalier’s Photographe à verres combinés, introduced in 1840 (see Figure 3.28). According to Charles Fabre: . . . [Chevalier’s lens] was composed of two achromatic elements, one being a positive meniscus lens with the convex side turned towards the focusing screen, and the other being a bi-[convex] or plano-convex lens turned towards the object being viewed. Between the front of the lens and the subject a stop was placed. The front

Figure 3.28 Three views of Chevelier’s Photographe à verres combinés. The top left illustration shows the lens being used for landscape and architectural subjects, with a stop located in front of the elements, in combination with a shortened lens barrel. The top right shows the same arrangement with a reflecting prism installed to laterally correct the focused image in making daguerreotypes. The lower left shows the lens being used at full aperture, in combination with a lengthened focusing barrel. The lens could also be used as a landscape lens, with a single lens element (L). Detail from a folding plate at the end of Charles Chevalier, Nouvelles instructions sur l’usage du daguerréotype (Paris, 1841). Reproduced by permission of the Department of Printing and Graphic Arts, Houghton Library, Harvard College Library.

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lens element could be replaced by a lens with a shorter focal length, and the rear lens could be used as an individual [landscape] lens.36

Unfortunately, Fabre’s description fails to supply any design specifications, most notably combined lens and component lens focal lengths. Chevalier’s own remarks are likewise vague, supplying little more than a few lens diameter measurements. In the search for these specifications, I have thus far been fortunate to make the acquaintance of Ruud Hoff, a collector and dealer in antiquarian photographic equipment in Amsterdam who has a Photographe à verres combinés dating to 1853 in his personal collection. In kind response to my inquiries, Mr. Hoff made some approximate measurements of his lens’s component lens diameters, component lens focal lengths, and combined lens focal lengths, supplying me with the following information for an object focused at a distance of 3 meters:

• The rear element has a diameter of 82 mm and an individual focal length of approximately 470 mm.

• The front element for landscapes has a diameter of 55 mm • • • •

and an individual focal length of approximately 900 mm. The front element for portraits has a diameter of 55 mm and an individual focal length in excess of 2 meters. The rear element used in tandem with the front element for landscapes has a focal length of 230 mm, as measured from the rear element. The rear element used in tandem with the front element for portraits also has a focal length of 230 mm, as measured from the rear element. The three elements used together have a focal length of 250 mm, as measured from the rear element.

Chevalier’s Photographe à verres combinés has been treated as little more than a footnote by photo-historians. A quaint example of French patriotic chauvinism, exemplified by its being awarded a platinum medal by a Parisian société d’encouragement because the society could not bear to give the highest honor to the Petzval Portrait Lens, or système allemand as it was known at the time. Alleged technical shortcomings can be summed up in the words of Rudolf Kingslake: “. . . [Chevalier’s] lens was not all that good, and although it was manufactured for some 20 years by Chevalier and his son, it could in no way compete with the Petzval Portrait lens.”37 What is overlooked in this analysis is that the prevalence of the Petzval lens was a consequence of its being used in commercial portrait studios, which by and large produced daguerreotypes rather than calotypes. Due to the high precision of its circular definition, the Petzval lens was an obvious preference with the daguerreotype, which was capable of rendering extremely minute details. With the softer calotype process, however, preference for the Petzval Portrait Lens should not be automatically assumed. Rather, in many cases, Chevalier’s lens was preferred because it offered a more evenly dis119

tributed focus and illumination. For example, Guillot-Saguez, a French medical doctor who pioneered a variant calotype process (see Chapter 4), wrote that he preferred Chevalier’s Photographe à verres combinés to all others.38 Other examples can be found in an 1854 publication by Charles Chevalier, in which he assembled a number of supporters of his lens, significant among them being Henry Talbot and Frédéric Flachéron.39 Thomas Sutton’s remarks concerning the lens used by Flachéron may be noteworthy as well: “. . . [I]t is surprising that this form of lens should have gone out of fashion, and been supplanted by one in which everything is sacrificed to the central pencils.”40 And as late as 1862, under a chapter heading entitled “On the Most Proper Lenses for Photography on Paper,” E. de Valicourt continued to voice a preference for the Chevalier lens due to the loss of illumination and marginal focus to be found in the système allemand.41

Preliminary Considerations Regarding Construction Asymmetrical duplets may be easily assembled from two lenses having different focal lengths. Writing on this subject, Thomas Bolas offered the following encouraging remarks: Dissimilar lenses of the achromatised meniscus type may be combined into doublets with very good effect, and then the diaphragm should be placed not midway but at a distance proportional to the focal lengths of the two lenses. The photographer who works for pictorial effect only, need seldom or never go beyond the achromatised view lens either singly or in combination, and anyone who is mechanic enough to construct suitable mounts may at a small cost furnish himself with a useful battery of elements for combination. Further, it is often an excellent plan to combine an uncorrected spectacle lens with an achromatised lens. The wide latitude as regards centring is quite surprising; this latitude as regards centring only exists in the case of elements each of which is complete in itself. . . .42

Bolas’s remarks, dating to the heyday of the pictorialist era, offer little more than an extension of the Periskop lens given above. Similar in both cases is the locating of the stop in between the lens elements. Following Bolas’s advice, I have tried combining dissimilar elements with a stop located in the middle. I have yet to be truly satisfied with the result, due to curvature of field problems. Applying some recommendations made by Sutton to an asymmetrical configuration similar to Chevalier’s photographe à verres combinés, I arrived at a more satisfying arrangement, capable of a flat field covering quarterplate to half-plate, and ranging from f4 to f8, thus making it suitable for short exposure times and portraits. The secret to its success, I feel, has to do with the placement of the stop in front of the lens elements, rather than in between, and the extending of the lens barrel at 120

considerable distance in front of the lens elements, whereupon it acts as a lens shade. This introduces vignetting to a large extent, but the payback in clarity of focus with a wide aperture is quite remarkable. Once again, Sutton’s remarks on this effect are noteworthy here: Diffused light exists in the atmosphere, and if you wish to see distant objects clearly, you must look at them through a tube. The stars, for instance, are visible at noon-day from the bottom of a well. Bearing this principle in mind, an important addition should be made to every camera [here he is referring to lenses installed in the camera] in the shape of a long darkened tube in front. . . . A camera constructed on this principle would be equally suitable for views or portraits, because its lens would give as flat a field as an ordinary view lens, and splendid definition might be obtained by using a stop immediately in front of the front lens. By removing the stop, and working in a strong light with a full aperture, it would be suitable for taking instantaneous pictures.43

Note: In contrast with the procedural steps listed in the other chapters of this book, with lens construction it has been deemed more beneficial to list an idealized series of procedural steps since no exact lens specification can be expected to be obtainable on the market at any time. The following construction sequence is intended to serve as an example of the procedure to be followed in making an asymmetrical duplet portrait lens. Exact dimensions, as given in the example, will need to be adjusted to match the lens elements and format you are using. This being the case, it is recommended that you adopt the following guidelines in making the lens. These are adapted from Chevalier, Sutton, and Bolas, as discussed above, and are intended for a convertible lens for use with formats ranging from quarter-plate to half-plate, when used in combination, and whole-plate to 10≤ ¥ 12≤ when taken apart and used as a singlet landscape lens:

• Two positive elements of varying focal lengths are used, one being either bi-convex or plano-convex and the other being positive meniscus. • The lens elements should either be achromatic, or a combination of one achromatic and one uncorrected element. A successful combination seems to be an achromatic plano-convex lens and an uncorrected positive meniscus lens. • The ratio of the diameter of each lens element should be about 6 : 5, with the positive meniscus lens having the wider dimension of the two. For example, a positive meniscus lens with an 80 mm diameter and a plano-convex lens with a 65 mm diameter. • The focal length of the positive meniscus element should be long enough for it to serve as a landscape lens when used by itself. The bi-convex or plano-convex lens focal length can 121

range from somewhat shorter to considerably large than this. For example, a positive meniscus lens with a 480 mm focal length and a plano-convex lens with a 400 mm focal length. • The distance separating the two elements is determined by adding the individual focal lengths together and dividing the sum by 5 or 7 depending on the format being used. For example, in combining a 480 mm lens with a 400 mm lens, 480 is added to 400 to arrive at 880. 880 is then divided by 5 to come up with 176, which means that the elements are spaced apart 176 mm resulting in a flat field covering quarter-plate at f4 with pronounced vignetting. For a flat field covering half-plate at f8, divide by 7, which means that the elements are spaced apart 126 mm, resulting in less vignetting. • The lens barrel should be extended by about 1/5 of the absolute focal length to act as a shade. The absolute focal length may be obtained by using Grubb’s method, outlined above, or by applying equation 3.2, also given above. For example, in using equation 3.2, a 480 mm lens combined with a 400 mm lens at a distance of 180 mm would yield an actual focal length measuring 273 mm, which is then divided by 5 to arrive at 55. This means that the focusing barrel should extend 55 mm beyond the front element. Vignetting in this case would reduce the usable format to between quarter-plate and half-plate size, whereupon the resulting negative would normally be cut down to quarter-plate. • The stop, when used, is either placed in contact with the front of the lens or in between the lens elements at a proportional distance to their individual focal lengths. Prior to 1855, the stop was normally placed in front of the lens.

Construction Procedure: Asymmetrical Duplet Listed below are the procedural steps for constructing an asymmetrical duplet lens resembling Chevalier’s Photographe à verres combinés (see Figure 3.29). It utilizes an achromatic 79 mm diameter planoconvex lens with a 400 mm focal length, and an uncorrected 89 mm diameter positive meniscus lens with a 476 mm focal length. The lens elements are spaced 175 mm apart in a PVC lens barrel with a 4≤ inner diameter. This results in an actual focal length measuring 272 mm. Due to the length of the lens barrel and the extension of a lens shade in front of the lens elements, a significant amount of vignetting results, reducing the usable format to between quarterplate and half-plate. The lens is constructed as follows: 1. Using a saw and miter box, cut a 2-1/2≤ section of PVC, a 4-7/16≤ section, and a 4-5/8≤ section. These are to form the lens shade and the two sections of the lens barrel. 122

The stop is located here.

1"

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"

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32

79mm 89mm 4" 1" 42

79mm 34mm

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1116

2. In the same manner, cut five 1/2≤ sections of PVC and two 1≤ sections. These are to serve as retaining rings and spacers. 3. Taking the sections of PVC from step 2, remove a small portion of the O-shaped section from each with a handsaw so as to make them C-shaped (see Figure 3.17). This is most easily achieved by viewing each O-shaped section as a clock face, whereupon the two saw cuts are made between 4 o’clock and 5 o’clock and 7 o’clock and 8 o’clock. 4. Check the fit of the C-shaped sections by sliding them into the O-shaped sections from step 1. 5. Remove the C-shaped sections from the O-shaped sections and trim off any excess plastic remaining on the edges of the PVC with a utility knife. 6. Mark the outside of the 1≤ C-shaped sections so that 1/2≤ is indicated. Mark the inside of the 4-5/8≤ O-shaped section 1/2≤ from one end. 7. Apply contact cement to the 1≤ C-sections and to one of the 1/2≤ C-sections. Install and glue one of the 1≤ Csections to one end of the 2-1/2≤ lens shade from step 1 so that 1/2≤ of the C-section is sticking out. Install and glue the other 1≤ C-section to one end of the 4-7/16≤ section from step 1, so that 1/2≤ of the C-section is stick-

Figure 3.29 272 mm focal length, asymmetrical duplet lens, stopped down to f8. Front and side views.

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8.

9. 10.

11.

12.

13. 14.

15. 16. 17.

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ing out. Install and glue the 1/2≤ C-section 1/2≤ into the 4-5/8≤ section. Allow to dry for a few hours. In an area with adequate ventilation, spray paint the joined sections from step 7 and all of the remaining sections flat black. Hold the can of spray paint at a distance of about one foot away so as to avoid drip marks. Allow to dry. Turn the pieces over and spray paint the remaining unpainted surfaces. Allow to dry. Taking a sheet of black construction paper, cut a piece measuring 5≤ ¥ 5≤. Find the center by drawing diagonal lines between corners. Then place a compass at the center and mark a circle with a radius of 2≤. Adjust the compass and mark a second circle with a radius of 17 mm, sharing a common center with the first one. Place the paper on a sheet of plate glass and, using an X-acto knife, cut along the two circles. Cut the circles by turning the paper on the glass, holding the knife in a vertical, stationary position rather than dragging the knife across the paper. The circular formation that results is the stop. Taking a sheet of 3/16≤ black foam-core, cut a piece measuring 5≤ ¥ 5≤. Find the center by drawing diagonal lines between the corners. Then place a compass at the center and mark a circle with a radius of 2≤. Adjust the compass and mark a second circle with a radius of 44.5 mm, sharing a common center with the first one. Repeat step 12, using a sheet of 1/2≤ black foam-core. This time, however, mark a second, interior circle having a radius of 39.5 mm. Place one of the pieces of foam-core on a cutting surface, and begin cutting the inner circle with an X-acto knife. Make sure that the blade remains in a vertical, upright position when the cuts are made, and do not try to cut through all of the foam-core at once. Rather, cut it so that a series of dotted marks become visible on the backside. Once the dotted outline of the circle is formed, turn the foam-core over and finish cutting by connecting the dotted marks with the knife. This ensures a more even cut. Repeat step 14, cutting the larger circle. The resulting O-shaped piece of foam-core is to hold one of the lens elements in place. Repeat steps 14 and 15 for the other piece of foam-core. This is to hold the other lens element in place. Using lens tissue, slide the 89 mm diameter, positive meniscus lens into the hole cut into the 3/16≤ piece of foam-core so that the concave side of the lens element is flush with one side of the foam-core. The fit should be a little bit snug rather than loose. Remove any fingerprints

as needed with lens cleaning tissue, using a drop of lens cleaning solution if need be. 18. Repeat step 17, installing the 79 mm diameter, achromatic, plano-convex lens element into the remaining piece of foam-core so that the flat side of the lens element is flush with one side of the foam-core. 19. Referring to the diagram (see Figure 3.29), assemble the lens so that the lens elements are oriented as shown. Start by sliding two 1/2≤ C-sections and the positive meniscus element into one end of the 4-7/16≤ section of lens barrel. Then connect the 2-1/2≤ lens shade to the end of the lens barrel with the lens, sliding the lens element further into the lens barrel via the glued 1≤ C-section. Once the lens element and the lens shade are in place, install the remaining two 1/2≤ C-sections and the achromatic, plano-convex lens element in the 4-5/8≤ section. Then connect this section to the other part of the assembly. The lens may be used at full aperture or stopped down to f8. To install the stop, remove the lens shade and place the stop against the 1/2≤ C-section holding the positive meniscus lens in place. Then replace the lens shade. The lens barrel is cut into two sections to convert it into a landscape lens. To achieve this, remove the 4-7/16≤ section of lens barrel, the positive meniscus lens, and the lens shade. By placing a stop against the 1/2≤ C-section glued in the 4-5/8≤ section of lens barrel, and using a removable 1/2≤ C-section from the 4-7/16≤ section of the lens barrel to hold it in place, the achromatic lens may then be used as a singlet with a 400 mm focal length.

THE SYMMETRICAL TRIPLET The symmetrical triplet represents a modification and extension of the symmetrical duplet. It utilizes two identical, opposing planoconvex lenses with a double-concave lens in between to flatten and minimize curvature of field. Otherwise, the two kinds of lenses are quite similar. Like the symmetrical duplet, the symmetrical triplet is primarily designed to eliminate curvilinear distortion, making it especially useful for architectural studies.44

Historical Background The development and first use of the symmetrical triplet lens is attributed to Thomas Sutton (see Figure 3.30). Other triplets preceded his design, but they were in no way symmetrical, consisting for the most part of a middle lens element added to an asymmetric duplet to lengthen or shorten the focal length. According to Sutton’s

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Figure 3.30A and B Two midnineteenth-century depictions of Sutton’s Triplet. (A) Reprinted from D[ésiré] v[an] Monckhoven, Traité d’optique photographique (Paris, 1866), 115, fig. 61. (B) Reprinted from Thomas Sutton, “A New View-Lens,” Journal of the Photographic Society, no. 78 (February 5, 1859), 172, fig. 6.

A

B

own remarks, as well as those of readers of the Journal of the Photographic Society, Sutton’s Triplet was allegedly manufactured for a short period by Andrew Ross. The lens was stopped down to f32 and f64, with stops being placed in contact with the front side of the double concave element. Due to the absence of surviving examples, however, the lens does not appear to have been a commercial success, perhaps due to the small apertures employed or to the death of Ross in 1859. Other triplets were introduced shortly thereafter, chief among them being an asymmetric design developed in 1862 by John Dallmeyer, who had worked for Ross until 1859.45 Just about the only triplet lens design coming close to Sutton’s symmetrical design was the Cooke triplet, designed by Dennis Taylor in 1893. In this case, the stop was located to the rear of the central bi-concave element. Used at full aperture, or f4, it had a circle of definition measuring approximately 13°, so it was extremely narrowangle. Nevertheless, the design was highly influential on later triplet modifications. Taylor’s working method is worth mentioning. According to Rudolf Kingslake, “. . . Taylor worked entirely by algebraic formulae, which he developed himself, and he claimed that he never 126

traced any rays. When the design was as good as he could make it, the actual lens was fabricated, and examination of the image on a lens-testing bench suggested changes that should be made to improve the performance.”46

Preliminary Considerations Regarding Construction Symmetrical triplets are to be assembled from two identical plano-convex lenses with a bi-concave lens in between. The distance separating the plano-convex lenses from the bi-concave lens is identical. Stops are to be used in contact with the bi-concave lens, either on the frontside or backside. Sutton specified the frontside, but as this results in a very slight amount of barrel distortion, I prefer to place the stop in contact with the backside, which corrects this and yields a slightly flatter field. Used full aperture, the circle of definition is approximately 15°, making it very narrow-angle, although this may be useful for soft-focus pictorialist effects. Note: In contrast with the procedural steps listed in the other chapters of this book, with lens construction it has been deemed more beneficial to list an idealized series of procedural steps since no exact lens specification can be expected to be obtainable on the market at any time. The following construction sequence is intended to serve as an example of the procedure to be followed in making Sutton’s Triplet. Exact dimensions, as given in the example, will need to be adjusted to match the lens elements and format you are using. This being the case, it is recommended that you follow certain guidelines in making the lens. The following have been adapted from Sutton’s own descriptions of his lens, from which a variant possibility suggested by the later Cooke Triplet is also included:47

• Two identical, achromatic plano-convex lenses are to be used with a smaller diameter, uncorrected bi-concave lens. The positive focal length of each plano-convex lens should be slightly longer than the negative focal length of the biconcave lens, resulting in a combined positive to negative focal length ratio of about 8 : 13. For example, two planoconvex lenses, each having a positive focal length of 250 mm, could be used with a bi-concave lens having a negative focal length of 200 mm since the resulting combined ratio of 125 : 200 (or a quotient of 0.625) is very close to 8 : 13 (or a quotient of 0.6153846). • The distance between the plano-convex lenses should be approximately 1/5 to 1/6 their individual focal length, with the bi-concave lens placed in the middle of this distance. For example, with the two 250 mm focal length planoconvex lenses given above, the distance separating them would be 42 to 50 mm, with the bi-convex lens located 21 to 25 mm in between. 127

• For the best possible definition, a small stop (for example, f32 to f64) should be used, placed in contact with the backside of the bi-concave lens. This results in a maximum circle of definition measuring approximately 59°. • Uncorrected plano-convex lens elements may also be substituted for the achromatic elements, with the necessary focusing adjustments being made prior to exposing the negative.

Construction Procedure: Sutton’s Symmetrical Triplet Listed below are the procedural steps for constructing a symmetrical triplet lens resembling Sutton’s Triplet. It utilizes two achromatic, 51 mm diameter plano-convex lenses, each of them with a 180 mm focal length, and an uncorrected, bi-concave lens having a 38 mm diameter and a 150 mm negative focal length. The plano-convex elements are spaced 36 mm apart, with the bi-concave lens exactly in between, in a PVC lens barrel with a 3≤ inner diameter. This results in an actual focal length of 225 mm. Used with a 61/2≤ ¥ 8-1/2≤ format negative, it has a 62° wide-field angle of view. Refer to the diagram (see Figure 3.31) in constructing the lens as follows: 1. Using a saw and miter box, cut a 1-9/16≤ section of PVC and a 7/8≤ section of PVC. These are to serve as the lens barrel. 2. In the same manner, cut two 5/16≤ sections of PVC and two 5/8≤ sections of PVC. These are to serve as retaining rings for the lens. 3. Taking the sections of PVC from step 2, remove a small portion of the O-shaped section with a handsaw so as to make them C-shaped (see Figure 3.17). This is most easily achieved by viewing each O-shaped section as a clock face, whereupon the two saw cuts are made between 4 o’clock and 5 o’clock and 7 o’clock and 8 o’clock. 4. Check the fit of the C-shaped sections by sliding them into the two O-shaped sections from step 1. 5. Remove the C-shaped sections from the O-shaped sections and trim off any excess plastic remaining on the edges of the PVC with a utility knife. 6. In an area with adequate ventilation, spray paint all of the pieces flat black. Hold the can of spray paint at a distance of about one foot away so as to avoid drip marks. Allow to dry. 7. Turn the pieces over and spray paint the remaining unpainted surfaces. Allow to dry. 8. Taking a sheet of black construction paper, cut a piece measuring 4≤ ¥ 4≤. Find the center by drawing diagonal lines between corners. Then place a compass at the center and mark a circle with a radius of 1-1/2≤. Using a circle 128

1"

32 3"

1"

22

The stop is located here.

51mm

5" 5" 16

3"

8

16

1"

32

3"

51mm

38mm

38mm

5" 3"

8

16

3" 16

5" 16

(foam-core) (foam-core) (foam-core) 9"

7"

1 16

8 7"

2 16

template, mark a circle with a 4 mm diameter, sharing a common center with the larger one. 9. Place the paper on a sheet of plate glass and, using an Xacto knife, cut along the two circles. Cut the circles by turning the paper on the glass, holding the knife in a vertical, stationary position rather than dragging the knife across the paper. The circular formation which results is the stop. 10. Taking a sheet of 3/16≤ black foam-core, cut three pieces measuring 4≤ ¥ 4≤. Find the center of each by drawing diagonal lines between the corners. Then place a compass at the center of each piece and mark a circle with a radius of 25.5 mm for two of the pieces, and a radius of 19 mm for one of the pieces. Then mark a second circle for all of the pieces with a radius of 1-1/2≤, sharing the same center with the previously drawn circles. 11. Place one of the pieces of foam-core on a cutting surface and begin cutting the inner circle with an X-acto knife. Make sure that the blade remains in a vertical, upright position when the cuts are made, and do not try to cut through all of the foam-core at once. Rather, cut it so that

Figure 3.31 225 mm focal length, symmetrical triplet lens. Front and side views.

129

12. 13. 14.

15.

16.

17.

18.

19.

20.

21.

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a series of dotted marks become visible on the backside. Once the dotted outline of the circle is formed, turn the foam-core over and finish cutting by connecting the dotted marks with the knife. This ensures a more even cut. Repeat step 11, cutting the larger circle. The resulting Oshaped piece of foam-core is to hold one of the lens elements in place. Repeat steps 11 and 12 for the other two pieces of foamcore. These are to hold the other lens elements in place. Using lens tissue, slide the bi-concave lens element into the foam-core with the smaller hole in the center, making sure that the sides of the lens are parallel with the sides of the foam-core. The fit should be a little bit snug rather than too loose. Remove any fingerprints as needed with lens cleaning tissue, using a drop of lens cleaning solution if need be. Repeat step 14, installing each plano-convex element into the remaining pieces of foam-core. In sliding the planoconvex lenses, make sure that the flat side of the lens element is flush with one side of the foam-core. The fit should be a little bit snug rather than loose. Taking one of the 5/16≤ C-shaped rings from step 2, slide it into one end of the 1-9/16≤ piece from step 1. Adjust as needed so that the C-ring is flush with the end of 19/16≤ piece. Taking one of the plano-convex lens elements installed in the foam-core from step 15, slide it into the tube and against the C-ring from step 16 so the foam-core with the convex side of the lens element is resting against the C-ring. Taking one of the 5/8≤ C-shaped rings from step 2, slide it into the remaining part of the 1-9/16≤ section until it is pressed against the foam-core holding the lens element. About 7/16≤ should remain at the end of the 1-9/16≤ tube afterwards. Blow away any loose paint that has fallen onto the lens element. Slide the piece of foam-core with the bi-concave lens into the 1-9/16≤ section so that it is resting on the 5/8≤ C-ring installed in step 18. About 1/4≤ should remain at the end of the 1-9/16≤ tube afterwards. Repeat steps 16 through 18, installing the remaining plano-convex lens element into the 7/8≤ section of PVC using the remaining 5/16≤ and 5/8≤ C-rings. About 1/4≤ of the 5/8≤ C-ring should be above the end of the 7/8≤ section afterwards. Taking the black construction paper from step 9, slide it into the 1-9/16≤ section so that it is resting against the foam-core with the bi-concave element installed in step 19.

22. Connect the 7/8≤ section to the 1-9/16≤ section, forming the complete lens barrel. The convex sides of the planoconvex lens elements should be facing outwards with the bi-concave lens element in between and the stop located just behind it. The lens is now complete. The lens barrel is cut into two sections in order to facilitate the changing of f-stops, which in the construction example has a diameter of 4 mm, or approximately f64. In this way, two additional stops may be made from black construction paper, one with a hole diameter measuring 5 mm, or f45, and the other with a hole diameter measuring 7 mm, or f32. Stops are easily changed by removing the 7/8≤ section at the rear of the lens and changing the pieces of construction paper. In changing the stops, be careful to prevent the bi-concave element from falling out as it is held in place by the rear half of the lens barrel.

LENS BOARDS AND LENS CAPS All of the lenses described in this chapter are to be connected to the cameras described in Chapter 2 by means of a lens board. In the case of a sliding box-camera, this consists of a 5≤ ¥ 5≤ piece of Luan with a circular hole cut out of the center matching the outer diameter of the lens barrel. In the case of a folding camera, this consists of a 13-1/16≤ ¥ 12-1/8≤ piece of Luan with an additional brass collar attached to the circular hole to allow for movement and focusing of the lens barrel. In both cases, however, lens focal length needs to be in accordance with the length of the camera in question. To some extent, this focal length may be adjusted by positioning either the lens barrel or collar a bit to the rear or front, prior to attaching it permanently. Exposures are to be made by the means of a lens cap, which is removed and replaced in front of the lens in order to make the exposure. The lens cap also serves to protect the lens from being scratched when moving it from one location to another. The construction of the lens cap is in all cases the same, only varying according to the diameter and length of the lens barrel.

Construction Procedure: Sliding Box-Camera Lens Board Listed below are the steps for constructing a lens board for use with the lenses described in this chapter and the sliding box-camera described in Chapter 2. Refer to the illustration (see Figure 3.32) for the construction procedures that follow: 1. With a straight-edge and a utility knife, cut a 5≤ ¥ 5≤ section of Luan. Make scoring passes with the knife rather than trying to cut through the entire thickness at once. 131

A Figure 3.32A, B, and C Cutting a hole in the lens board. (A) A piece of Luan plywood with marks indicating the hole for the lens barrel. (B) Cutting the hole with a utility knife. (C) The lens board with hole cut out. Note: the lens board shown here is for use with the folding-camera described in Chapter 2. In the case of a sliding box-camera lens board, the hole is to be located at the exact center of the board.

132

B

C

2. Once the piece is cut out, check the fit with the boxcamera by installing it in the front of the camera (see Chapter 2). Sand the edges and corners of the board as needed. 3. With the lens board removed from the camera, locate the center of the board by drawing lines that connect the opposite corners, forming an “X.” 4. Repeat step 3 for the other side of the board. 5. Measure the outer diameter of the lens barrel in question. With a compass, mark out a circle matching this diameter with its center at the center of the lens board. 6. Repeat step 5 for the other side of the board. 7. Taking the utility knife, cut out the circles drawn on both sides of the board. Once again, make scoring passes with the knife rather than trying to cut through the entire thickness at once. Switch sides of the board from time to time to ensure an even and accurate cut. 8. Once the circular hole is formed, check the fit of the lens barrel by sliding it into the hole in the board. Sand or cut the hole as needed until the fit is slightly snug. Note: To avoid needlessly scratching the painted surface of the PVC, check the fit with an unpainted scrap piece of PVC first. 9. Once the fit of the lens barrel has been verified, make a series of indicating marks on the outside of the lens barrel in pencil to ensure that the lens board will be attached squarely. Normally, this is done by finding the center of the length of the lens barrel, and then marking short lines in pencil approximately 1/16≤ apart from the center so as to indicate the 1/8≤ thickness of the Luan board. Note: If the focal length needs to be adjusted to conform to the length of the camera, these marks may be made more towards the front or rear of the lens barrel as needed, just so long as the marks are equidistant from the end in question. 10. Repeat step 9 three more times, rotating the lens barrel a quarter-turn each time so that the lens board may be lined up with the entire circumference of the lens barrel.

11. Slide the lens board onto the lens barrel, lining it up with the indicating marks made in steps 9 and 10. Using a caulk gun, place vinyl adhesive caulk on both sides of the lens board exactly where it meets the lens barrel. Smooth the adhesive out with a finger and then allow the entire assembly to dry for a few hours. This is best done by supporting the weight of the assembly by the lens barrel rather than the board. 12. During the first few minutes of gluing, while the vinyl adhesive caulk is still setting up, check the positioning of the board on the barrel from time to time with a square, adjusting it as needed. 13. Using flat black enamel paint and a 1-1/2≤ brush, paint the lens board. Allow it to dry a few hours, then add a second coat as needed.

Construction Procedure: Folding-Camera Lens Board The steps involved in constructing a lens board for the foldingcamera are almost the same as for the box-camera. The only differences are that the lens board is cut to 13-1/16≤ ¥ 12-1/8≤, and rather than attaching the lens barrel directly, you will use a piece of brass shim-stock to form a collar for the lens barrel. Refer to the illustration (see Figure 3.33) in relation to the following procedural steps for making the collar of the lens board: 1. Taking two 2≤ ¥ 12≤ pieces of brass shim-stock, tape them together using strapping tape so that they form a combined dimension measuring 2≤ ¥ 16≤. 2. Cut a 2≤ ¥ 16≤ piece of dense black foam, and glue it to one side of the brass shim-stock from step 1 using contact cement. This is to keep light reflectance to a minimum and to keep the brass shim-stock from scratching the painted finish of the lens barrel. 3. Wrap the shim-stock securely around the lens barrel, with the side of the shim-stock and the black foam facing the lens barrel. 4. Holding the shim-stock in place, place a 5≤ diameter hose clamp around it. Tighten the hose clamp with a screwdriver until the shim-stock is snug against the PVC. 5. With the hose clamp in place, mark and cut out a hole in the Luan based on the outer diameter of the shim-stock, rather than the PVC. 6. Having cut out the hole in the Luan, glue the shim-stock to the lens board using vinyl adhesive caulk. Use a finger to smooth out the adhesive so that no gaps are remaining. Allow the adhesive to dry for a few hours with the PVC in place. 133

A

B

C

D

E

F

G

H

Figure 3.33A, B, C, D, E, F, G, and H Constructing a foldingcamera lens board. (A) Component parts of the assembly. (B) The brass shim-stock with black foam glued to one side. (C) Wrapping the brass shim-stock around the painted lens barrel. (D) Tightening the hose clamp with a screwdriver. (E) The lens board with a hole cut to match the outer diameter of the brass shim-stock. (F) Adding black vinyl adhesive caulk with a caulk gun. (G) Smoothing out the adhesive with a finger. (H) Allowing the completed assembly to dry a few hours.

7. Once the adhesive has dried, loosen the hose clamp slightly so that the lens barrel may slide back and forth. Then tighten the hose clamp until the lens board is held securely. 8. Using flat black enamel paint and a 1-1/2≤ brush, paint the lens board, taking care to avoid the lens barrel and hose clamp. Allow it to dry a few hours, then add a second coat as needed. Provided that the fit is secure, this assembly allows the lens to be moved back and forth over the entire length of the lens barrel, simultaneously keeping it square in relation to the film plane. Proper focus is achieved by moving the lens back and forth, rather than moving the camera body. Using uncorrected lenses, the focusing adjustment for chromatic aberration is made by measuring the distance from the film plane to the front of the lens barrel, multiplying that distance by 0.975, and then moving the lens back accordingly.

134

Figure 3.34A and B Making a lens cap. (A) A circular piece of black foam-core cut to match the outer diameter of the lens barrel, and a strip of black card-stock, which has been taped after wrapping it around the lens barrel. (B) The lens cap with the foam-core glued to the card-stock strip, finished and installed upon the lens barrel.

A

B

Construction Procedure: Lens Caps Given the relatively slow exposure times in using calotype paper negatives, ranging from a few seconds to several minutes, a lens cap is all that is needed in making the exposure. This makes for a very simple affair, whereupon the lens cap is removed from the lens in order to make an exposure and replaced on the lens in order to terminate the exposure. And since the size of the lens cap varies according to the diameter and length of the focusing barrel for each lens, a generalized set of procedures are given below. Refer to the illustration (see Figure 3.34) in relation to the following procedural steps: 1. Depending on the outer diameter of the PVC lens barrel in question, mark out and cut a circular piece of 3/16≤ black foam-core to match using a compass and an X-acto knife. 2. With a utility knife, cut a 1≤ wide strip of black card-stock in which the length exceeds the circumference of the circle cut in step 1 by 1≤ to 2≤. 3. Wrap the strip cut in step 2 around the lens barrel being used. Add some glue to the 1≤ to 2≤ of overlapping cardstock, taking care not to glue it to the lens barrel, and hold the strip in place either by taping it or wrapping one or two rubber bands around it. Allow this to dry for a few hours. 4. Once the glue has dried, remove the card-stock strip from the lens barrel. Slide the circular piece of foam-core from step 1 into the resulting circular form, checking the fit. 5. Remove the foam-core from the strip, and then line the edges of the foam-core with black vinyl adhesive. Slide it

135

back into the card-stock strip so that it is flush with one end of the strip. Allow to dry for a few hours. Once it has dried, check the area where the strip is glued to the foamcore for light-leaks, adding extra vinyl adhesive if needed. When dry, the lens cap is ready to be used.

NOTES 1. The terms singlet, duplet, and triplet are given in Rudolf Kingslake, Lenses in Photography: The Practical Guide to Optics for Photographers (Garden City [NY]: Garden City, 1951), 119–131. 2. A description of simple lens elements is given in D[ésiré] v[an] Monckhoven, Traité d’optique photographique (Paris: Victor Masson, 1866), 52–53. 3. A description of combined lens elements is given in Monckhoven, Traité d’optique photographique, 93–95. 4. For an idea of the trigonometric complexity involved in determining glass and lens curvature combinations, see A[lexander] E[ugen] Conrady, Applied Optics and Optical Design, 2 vols., edited and completed by Rudolf Kingslake (New York: Dover Publications, 1992); and Rudolf Kingslake, Lens Design Fundamentals, (New York: Academic Press, 1978). 5. For an idea of the trigonometric complexity involved in arriving at certain compound lens configurations, see Conrady, Applied Optics; and Kingslake, Lens Design Fundamentals. 6. Mathematical methods of determining the focal length, effective aperture, and transmittance factors are given in Allen R. Greenleaf, Photographic Optics (New York: Macmillan, 1950). I am indebted to Richard Koolish for lending me this book from his personal collection, as well as for directing me towards several other books cited in this chapter. 7. For more about the principal focus and absolute focal length, along with Grubb’s method for determining the absolute focal length, see Monckhoven, Traité d’optique photographique, 70–74. 8. For more on the angle of view, see Tho[ma]s Bolas and George E. Brown, The Lens: A Practical Guide to the Choice, Use, and Testing of Photographic Objectives (London: Dawbarn and Ward, 1902), 27–32. 9. The definition of normal-angle, narrow-angle, wide-field, and wideangle is taken from Kingslake, Lenses in Photography, 8–9, 42. 10. For more on the discrepancy concerning the absolute focal lengths of portrait lenses, see Monckhoven, Traité d’optique photographique, 75 n. 1. 11. Field of view and the circle of definition are defined in Kingslake, Lenses in Photography, 6–8. 12. Circle of illumination is explained in Kingslake, Lenses in Photography, 101–102; and Bolas and Brown, The Lens, 30–32. 13. For more on the actual aperture and effective aperture, and the methods for determining them, see Arthur Lockett, Camera Lenses: A Useful Handbook for Amateur and Professional Photographers, 2nd ed., rev. by H.W. Lee (New York: Pitman, 1947), 45–46. 14. Lens transmittance is discussed in Greenleaf, Photographic Optics, 49–53. 15. Spherical aberration is described in Monckhoven, Traité d’optique photographique, 80–86; and Kingslake, Lenses in Photography, 25–26. 16. Coma is described in Bolas and Brown, The Lens, 58–60; and Greenleaf, Photographic Optics, 39–41.

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17. For more on chromatic aberration, see Monckhoven, Traité d’optique photographique, 91–99; and Greenleaf, Photographic Optics, 44–47. 18. The method of adjusting the focus of an uncorrected lens for chromatic aberration is given in Monckhoven, Traité d’optique photographique, 144; and Bolas and Brown, The Lens, 74–75. 19. Curvature of field is described in Monckhoven, Traité d’optique photographique, 99–111; and Kingslake, Lenses in Photography, 37–39. 20. Curvilinear distortion is described in Monckhoven, Traité d’optique photographique, 111–116; and Kingslake, Lenses in Photography, 39–40. 21. Astigmatism is described in Monckhoven, Traité d’optique photographique, 116–125; and Lockett, Camera Lenses, 18–20. 22. For more on the use of landscape lenses, viewed in relation to curvature of field and curvilinear distortion, see Charles Fabre, Traité encyclopédique de photographie (Paris: Gauthier-Villars, 1889), v. 1, 65–74; Bolas and Brown, The Lens, 73–79; and Conrady, Applied Optics, v. 2, 777–790. 23. For more on the lens used by Niépce, see Helmut and Allison Gernsheim, L.J.M. Daguerre: The History of the Diorama and the Daguerreotype, 2nd rev. ed. (New York: Dover, 1968), 63. For more on the Wollaston meniscus lens, see Rudolf Kingslake, A History of the Photographic Lens, (Boston: Academic Press, 1989), 23–26; and Monckhoven, Traité d’optique photographique, 127–128. 24. For more on Chevalier’s achromatic, landscape lenses, see Kingslake, Photographic Lens, 26–28; and Monckhoven, Traité d’optique photographique, 128–134. 25. The distinction to be made between old form and new form landscape lenses is discussed in Monckhoven, Traité d’optique photographique, 133–138; and Fabre, Traité encyclopédique de photographie, 67–74. 26. The general specifications of old form landscape lenses are given in Monckhoven, Traité d’optique photographique, 128, 134. 27. For more on Buron, see E. de Valicourt, Nouveau manuel complet de photographie sur métal, sur papier, et sur verre (Paris: Librairie Enyclopédique de Roret, 1862), v.1, 7; and Fabre, Traité encyclopédique de photographie, v.1, 66, 99, 142. 28. For the angle of view, curvature of field, and design specifications of various mid-nineteenth-century symmetrical duplet lenses, see Monckhoven, Traité d’optique photographique, 114–116, 138–146; and Fabre, Traité enyclopédique de photographie, 78–94. For the construction of symmetrical duplet lenses, see Bolas and Brown, The Lens, 74, 79–87; and Conrady, Applied Optics, v. 2, 791–801. 29. The early use of symmetrical lenses is discussed in Kingslake, Photographic Lens, 49. 30. For more on Sutton’s Panoramic lens, see Kingslake, Photographic Lens, 49–51; and Monckhoven, Traité d’optique photographique, 142–142. For more on Steinheil’s Periskop, see Kingslake, Photographic Lens, 53–54; and Monckhoven, Traité d’optique photographique, 144–146. 31. For more on the Wollensak Periskop variant, see Kingslake, Photographic Lens, 56. 32. The exact specifications of Steinheil’s Periskop are given in Monckhoven, Traité d’optique photographique, 144–145. 33. Background information concerning the Petzval Portrait Lens has been taken from Fabre, Traité encyclopédique de photographie, v.1, 95–99. 34. Sutton’s description of the Petzval Portrait Lens is taken from Thomas Sutton, A Dictionary of Photography (London: Sampson Low, 1858), 264–265.

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35. Sutton, A Dictionary of Photography, 264. 36. Fabre, Traité encyclopédique de photographie, v.1, 98. Fabre erroneously described the lens as having a bi-concave lens element instead of a biconvex element. 37. Kingslake, Photographic Lens, 35. 38. [A.] Guillot-Saguez, Méthode théorique et pratique de photographie sur papier (Paris: Victor Masson, 1847), 8. 39. Charles Chevalier, Guide du photographe (Paris: Charles Chevalier, 1854), Pt. 3, 34–35, 40. 40. Sutton, A Dictionary of Photography, 61. 41. Valicourt, Nouveau manuel complet, v.2, 8–10. 42. Bolas and Brown, The Lens, 79–80. 43. Sutton, A Dictionary of Photography, 61. 44. For a description of the symmetrical triplet, see Monckhoven, Traité d’optique photographique, 115–116; and Thomas Sutton, “A New ViewLens,” Journal of the Photographic Society, no. 78 (February 5, 1859): 169–173; and Thomas Sutton, “Description of a New Photographic Lens, Which Gives Images Entirely Free from Distortion,” Journal of the Photographic Society, no. 90 (October 15, 1859): 58–59. 45. For the production of Sutton’s Triplet by Andrew Ross, see Sutton, “A New View-Lens,” 170. For a description of Dallmeyer’s triplet lens, see Monckhoven, Traité d’optique photographique, 154–157. For biographical information concerning Ross and Dallmeyer, see Rudolf Kingslake, Photographic Lens, 221, 271. 46. The Cooke Triplet and Taylor’s working method are described in Rudolf Kingslake, Photographic Lens, 103–106; also see, Greenleaf, Photographic Optics, 75–78. 47. For the general specifications of Sutton’s Triplet, see Sutton, “A New View-Lens,” 172; and Sutton, “New Photographic Lens” 59. For the modifications suggested by Cooke’s Triplet, see Kingslake, Photographic Lens, 104, fig. 7.1; and Greenleaf, Photographic Optics, 20, fig. 9.

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4 Calotype Paper Negatives This chapter concerns the making of paper negatives with contemporary materials. Techniques presented herein are adapted from French calotype procedures from the late 1840s to early 1850s and represent a streamlining of techniques pioneered by William Henry Fox Talbot in the late 1830s–early 1840s.1 Two complementary procedures will be presented. The first is known as the wet-paper process. This procedure is intended to be used quickly, within a few minutes to a few hours after sensitizing. It allows for fine detail, relatively short exposure times with a wide aperture, and, therefore, portraiture. The second is known as the dry, waxed-paper process. Somewhat more grainy and less light-sensitive than the wet-paper process, it offers the advantage of being used for up to a few days after sensitizing. Thus, it lends itself better to distant landscape or architectural views, with the lens stopped-down for increased depth of field. With the exception of the waxing stage, the wet-paper process and the dry, waxed-paper process are similar with regard to the chemical sequencing involved. The first stage is known as iodizing. Here the paper is immersed in a solution of either potassium or ammonium iodide, to which sizing agents and trace amounts of bromide and chloride may or may not be added. The second stage is known as sensitizing. Here the iodized sheet is either floated upon or immersed in a solution of silver nitrate and acetic acid, whereupon the silver unites with the iodide in the paper to form the light-sensitive silver iodide. After being exposed to light in the camera, the negative moves to the third stage, known as developing. Here the paper is either floated upon or immersed in a solution of gallic acid, whereupon the previously invisible, latent image is revealed. Next the negative is rinsed before moving to the fourth and last stage known as fixing. Here the paper is immersed in a solution of sodium thiosulfate, rendering it impervious to light.

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CHEMICALS NEEDED Most of the chemicals needed to make negatives can be obtained from chemical suppliers listed in the appendix. The most essential are as follows:

• • • • •

Potassium iodide Silver nitrate Glacial acetic acid Gallic acid Sodium thiosulfate

The following ingredients are also needed for making negatives, and can be obtained from supermarkets, health-food stores, and artsupply stores:

• Distilled water (suggested for every step except the final • • • •

water wash) Beeswax A calcium carbonate-based cleanser (for example, Bon Ami“) White vinegar Kaolin (powdered china clay)

The following chemicals may be called for at times to fine-tune results, but they are not absolutely necessary:

• • • • •

Potassium bromide Sodium chloride Ammonium iodide Ammonium bromide Lactose (milk sugar)

The following ingredients may also be called for at times to finetune results, but they are not absolutely necessary:

• • • • • •

Potato or arrowroot starch Skim milk (1 percent milk-fat) Liquid rennet (used to coagulate milk) Honey Sugar (glucose) Ethyl alcohol (grain alcohol)

Note: in making paper negatives, the practitioner will be exposed to certain chemicals and acids demanding a requisite amount of protection from bodily harm. Neither the author nor the publisher takes any responsibility for injury or loss that may arise from using the materials and procedures as described. It is the reader’s responsibility to insure that his or her workplace is safe, well ventilated, and that he or she is wearing the proper protective covering for 140

a given chemical or procedural operation. Rubber nitrile or examination gloves, a plastic apron, an organic-vapor respirator, and safety goggles are to be worn as occasion demands. Request a Material Safety Data Sheet (MSDS) in ordering any chemical (chemical manufacturers or distributors must supply these upon request). Read it and be thoroughly familiar with each chemical’s properties before beginning any chemical operation. Follow the sequence of the procedural steps as indicated.2

MATERIALS NEEDED Many of the materials needed to make paper negatives are easily obtained from hardware, kitchenware, and art-supply stores. Note that glass is to be preferred over plastic whenever possible, since it is impermeable, allowing for chemical deposits to be easily cleaned. Metal utensils are to be avoided because they react with the chemicals being used. The following materials require little explanation:

• An assortment of glass beakers and liquid measures (measuring cups will suffice)

• An assortment of resealable, brown, glass bottles, 50 to • • • • • • • • • • • • • • • •

1000 ml (beer-bottles with hinged caps are especially recommended) Four, 100 ml eyedropper bottles Four to six glass or porcelain trays (Pyrex“ or enamelware baking trays work well) Plastic, picnic-style knives and spoons An iron (with a variable temperature control: rayon, poly/blend, cotton, etc.) Wooden clothespins and string Plastic funnels of varying sizes Coffee filters 2 to 4 square yards of fine, white linen Paper towels Small, disposable plastic drinking cups (for measuring chemicals) A few sheets of single strength, window-pane glass (cut to fit inside the film-holders designed in Chapter 1) Soft, cotton rags (old T-shirts work well) A few sheets of amber or rubylith film (cut 1/4≤ larger in both dimensions than the paper being sensitized) A few sheets of white, blotting paper (cut slightly larger than the format being used) An aluminum baking tray Paper for making negatives

Locations for lab and darkroom supplies, such as a triple-beam balance, glass graduates, and contact printing frames, will be found listed in the appendix. Another optional item, useful in developing 141

negatives on colder days, is a warming tray. It is assumed that the reader has access to a well-ventilated darkroom with a thermostat and safelight. As it serves as the negative substrate, selection of paper is one of the most crucial decisions you will have to make.3 Ideally, such a paper is 100 percent rag, moderately sized (sizing is a kind of glue that holds the paper fibers together, preventing the chemistry from sinking in too deeply) and ranges in weight thickness from 12 to 32 lb.4 It should also be free from watermarks, screen or laid markings, pinholes, and a strong tendency to curl when wet. In addition to this, it should have a good wet-strength, texture, and neutral pH. Avoid archival papers containing alkaline buffers since they cause spontaneous over-development. Always take the precaution of holding a sheet of a prospective paper type up to a light source and viewing it by transmittance. If you can see a pronounced screen marking, it should not be used. If the texture seems organic, less gridlike, it merits further investigation. Unfortunately, no modern paper answers to all of the above criteria. Nevertheless, it may be consoling to add that pretty much the same situation was present to mid-nineteenth-century photographers. Thankfully, today there are a number of papers on the market that will at least fulfill some of the above-mentioned criteria, thus allowing for calotype negatives to be made. These fall into three basic categories: architectural drafting vellums, graphic designers’ marker papers, and office stationery. These are more fully described as follows:

• Architectural drafting vellums. These are good papers to use, a chief advantage being their superb wet-strength, which prevents accidental tearing when handling while wet (see Figure 4.1). Fairly thin, they have a smooth texture and are relatively free from watermarks and pinholes. They can be sized to increase contrast by immersion in up to a 1 percent starch solution. One disadvantage is their tendency to curl when wet, which makes handling difficult with flotation. With practice, however, this difficulty can be overcome. Use of whey, or milk-serum, instead of a sizing agent, also eliminates this curling tendency (see Chapter 5). A good first choice for drafting vellum are National Printfast“ 80M (17 lb.), 80H (20 lb.), and 80EH (22.5 lb.), with Clearprint“ 1000H (16 lb.), 1020 (20 lb.), and 1025 (22 lb.) being a close second. • Graphic designers’ marker papers. Advantages are thinness, little tendency to curl, and starch sizing, which makes observing the iodizing and sensitizing stages easier. Their main disadvantage is poor wet-strength, which leads to tearing during the latter stages of processing (see Figure 4.2). This fragility rules out the possibility of adding much sizing, although immersion in a thin, 0.25 to 0.5 percent starch sizing solution can be used (see Chapter 5). Whey 142

Figure 4.1 A wet-paper process negative made with drafting vellum. This negative was made using National Printfast drafting vellum (20 lb.). There are no real staining problems and all of the corners are still intact after processing. This is indicative of a paper with a good wet-strength.

may also be substituted for sizing to increase contrast. Waxing marker papers prior to subsequent chemical operations strengthens them slightly, making their use with the dry, waxed-paper process particularly recommended. A good first choice for marker paper is Bienfang“ 360 (13.5 lb.). A second choice is Borden & Riley“ 100R (13.5 lb.). The latter paper has better wet-strength but suffers from more pronounced screen markings. • Office stationery. Chief advantages are that it has little tendency to curl when wet, and starch sizing. One disadvantage is that only limited format sizes are obtainable due to the presence of watermarks. Screen markings and pinholes also interfere at times, depending on paper thickness and the manufacturer. Because it is thicker, office stationery also needs to be fixed for longer periods of time. A good first choice for office stationery is Southworth“ Resumé R14CF (24 lb.) or 34E (24 lb.). These are sized with starch, have a very good texture, and do not curl when wet. They also have a good wet-strength, allowing for additional sizing in up to a 1 percent starch solution. One drawback is the presence of pinholes, which can lead to backside staining problems at times. A second choice is Crane“ Kid Finish BK 143

Figure 4.2 A wet-paper process negative made with marker paper. This negative was made using Bienfang 360 (13.5 lb.). In processing the negative, the two upper corners of the negative eventually came off. Also note the cracks starting to appear at the bottom of the negative. This is indicative of a paper with a poor wet-strength.

801S (32 lb.), although it suffers from a poorer wet-strength and more noticeable screen markings. Given the necessary chemical ingredients and materials, the following standard has been assumed for the procedures that follow. Thin paper refers to papers weighing 13 to 24 lb. per ream, with thick paper referring to those weighing 32 lb. per ream. Prior to iodizing, the paper is cut to 7-1/2≤ ¥ 9-1/2≤. After processing and drying, it can be trimmed to a final, whole-plate dimension of 6-1/2≤ ¥ 8-1/2≤, removing any stained margins. Plate glass refers to single-strength, window-pane glass, cut to 8≤ ¥ 10≤, which fits in the wet-paper process film-holder described in Chapter 1. Trays are 10-1/2≤ ¥ 15≤ Pyrex baking trays. Other format sizes may certainly be used instead of these, just remember to make the necessary adjustments concerning the dimensions of the glass plates and trays involved, and increase or decrease the volumetric amounts of chemical solutions as occasion demands. Note: the proper mixing of solutions merits consideration. For ease of conversion, these will usually follow the cookbook style of mixing favored by nineteenth-century practitioners. In this case, a liquid volume is given first, followed by the chemical ingredients and 144

acids. These are mixed in the order given, waiting until a chemical or acid has completely dissolved before adding the next ingredient. This method differs from the percentage-based approach, whereby a partial liquid volume is given first, followed by the chemicals, with additional liquid being added at the end to bring the total volume to an even measure. Therefore, it is important to note that any reference to a percentage solution using the cookbook method will at best be approximate. For example, 4 grams of potassium iodide added to 100 ml of distilled water by the cookbook method represents an approximate 4 percent solution; whereas, properly speaking, 4 grams of potassium iodide added to 75 ml of distilled water, followed by an additional amount of distilled water to bring the total volume to 100 ml is an actual 4 percent solution.

THE WET-PAPER PROCESS The wet-paper process, as presented here, stems from an original procedure developed by A. Guillot-Saguez, a Parisian physician who photographed in Rome during the mid-1840s, publishing a short treatise on the process in 1847.5 Guillot-Saguez’s technique offered two advantages over Talbot’s original negative-making procedure. The first was the elimination of an initial step using silver nitrate prior to iodizing. The second was the removal of gallic acid from the sensitizing solution, thereby avoiding a swift reduction of silver nitrate, which often ruined the negative prior to exposure. Later modifications to Guillot-Saguez’s procedure were introduced by Gustave Le Gray6 and Louis-Adolphe Humbert de Molard,7 which served to increase spectral light-sensitivity, improve tonality, and shorten development time. Significant practitioners of the wet-paper process included Édouard-Denis Baldus8 and Frédéric Flacheron.9 The wetpaper process often ascribed to Louis-Désiré Blanquart-Évrard is considered herein as a variant of Talbot’s original technique because it involved an initial step using silver nitrate.

Iodizing Procedure Iodizing takes place as a preliminary step in the wet-paper process and is done under ordinary room-light, either in the darkroom sink or in a bathtub. The violet iodide stains that result from paper-drippings are water soluble and easily removed with soap and water. Always wear an organic-vapor respirator, an apron, and nitrile gloves when mixing up iodizing solutions. Always wear an apron and examination gloves when handling the paper in solution. Clean up thoroughly after you have finished. Solutions may be disposed by pouring them down the drain. Refer to the diagram (see Figure 4.3) in relation to the following procedure for iodizing six sheets at a time: 1. Cut a dozen sheets of paper to size (for example, 7-1/2≤ ¥ 9-1/2≤), marking a marginal area of the backside of the 145

A

B Figure 4.3A, B, and C Stages in the iodizing procedure. (A) Positioning the paper for immersion. (B) Hanging the iodized sheet by one corner. (C) Drying the paper with a small piece of paper placed at the lowest hanging corner to absorb the excess solution.

C

Table 4.1

Iodizing Solution No. 1

Distilled water at 68°F (20°C) 500 ml Potassium iodide 20 grams Source: Adapted from [A.] Guillot-Saguez, Méthode théorique et pratique de photographie sur papier (Paris: V. Masson, 1847), 11. This formula is very economical, and can be reused for up to 3 months. With time and reuse, mold will form at the bottom of the bottle. Simply filter it off before using the solution again. Paper iodized with this solution has a shelf life of a few months. (For higher contrast, use a 0.25 to 1 percent starch solution or whey instead of distilled water. Adding starch or whey will reduce the useful life of the solution to a few days.)

paper with a soft pencil. This is to distinguish it from the frontside during subsequent operations. Other relevant marginal notations (for example, paper type, chemicals used, date, etc.) may be included here as well. 2. Mix up an iodizing solution (see Tables 4.1 to 4.3). 3. Pour the iodizing solution into a tray, filtering it with a coffee filter and funnel (use fine linen instead of a coffee filter in combination with a sizing solution). Filtering is to remove any foreign debris that could otherwise stain the negative. Wait a few moments for any lingering air bubbles to disappear. 4. Taking one sheet of paper at a time, hold it by two adjacent corners and then, curving it slightly, immerse it completely, sliding it beneath the surface of the iodizing solution. Remove any air bubbles that form on either side of the paper. (Thin papers should be transparent enough to see both sides simultaneously.) Turn it over once, twice, 146

Table 4.2

Iodizing Solution No. 2

Distilled water at 68°F (20°C) 500 ml Ammonium iodide 20 grams Ammonium bromide (optional) 2 grams Honey 25 grams Source: Adapted from a procedure attributed to A[dalbert] Cuvelier; cited in Charles Chevalier, Guide du photographe (Paris: Charles Chevalier, 1854), pt. 2, 46. Mid-nineteenth-century French calotypists claimed that using ammonium iodide instead of potassium iodide increased the sensitivity of the negative, but I have found that the opposite is true. Nevertheless, this formula does offer better tonal rendition and color sensitivity than iodizing solution number one (see Table 4.1). The solution can also be reused for up to 3 months. With time, mold will form at the bottom of the bottle. Simply filter it off before use. Paper iodized with ammonium iodide has a useful life of 1 to 3 days, so only iodize as many sheets as needed for a given session. (For higher contrast, use a 0.25 to 1 percent starch solution or whey instead of distilled water. Adding starch or whey will reduce the useful life of the solution to a few days.)

Table 4.3

Iodizing Solution No. 3

Distilled water at 68°F (20°C) 500 ml Potassium iodide 17.8 grams Potassium bromide 5.5 grams Sodium chloride 2.7 grams Source: Adapted from Gustave Le Gray, Traité pratique de photographie sur papier et sur verre (Paris: Germer Baillière, 1850), 4. This potassium iodide formula is lower-contrast version of iodizing solution number one (see Table 4.1), intended for scenes with deep shadows and bright highlights. With time, mold will form at the bottom of the bottle. Simply filter it off before use. Paper iodized with this formula has a shelf life of a few months. (For higher contrast, use a 0.25 to 1 percent starch solution or whey instead of distilled water. Using starch or whey will reduce the useful life of the solution to a few days.)

and, when the sheet is thoroughly wetted and face down again (30 to 60 seconds later), introduce the next sheet on top of the first, repeating for a maximum of six sheets. 5. After the last sheet has been completely immersed and wetted, agitate the tray from time to time, gently tipping the tray by one corner, until the first sheet has remained in the bath for a total of 5 minutes (for thicker papers, a total of 10 minutes). 6. Turn the entire stack of paper over. The first sheet should now rest on top, face up. Turn this sheet over one last time, again making sure that there are no air bubbles clinging to its surface. 7. Hang the first sheet up to dry by one corner using a line and clothespin. Position the paper so that it does not collapse upon itself when drying. Repeat for all other sheets 147

Figure 4.4 Iodizing paper in the nineteenth century. Note the use of chairs on either side of the trays. Reprinted from A[lphonse] Davanne, La Photographie: Traité théorique et pratique (Paris, 1888) v.1, 434, fig. 117.

in the iodizing solution, making sure each sheet leaves the iodizing bath approximately 30 to 60 seconds after the previous one. In this way, all sheets will be iodized for exactly the same amount of time. 8. Once the sheets are hanging to dry, place a small strip of paper in the lowest hanging corner of each sheet to absorb the excess solution that collects there. Failure to take this precaution results in a small silver iodide stain being formed in the corner of the negative. (Repeat steps 1 through 8 if more than six sheets are to be iodized.) 9. Leave the sheets hanging for a few hours until they are dry. Many papers will turn a rose or violet color, indicative of starch sizing in the paper reacting with the iodide. Other papers will not change much throughout the drying stage. Neither reaction seems to seriously affect the outcome of the negative. 10. Once the paper has dried, remove it from the line and flatten it, sandwiching the curled sheets of paper between two clean sheets of mat-board. Then rest a heavy weight on top of the pile for a few hours. Upon removal, the iodized sheets should be quite flat and are ready for sensitizing. Stored in an archival box, away from excessively humid conditions, they should keep for a few months.

Iodizing Solutions: Adjustments and Fine-Tuning Paper is most easily used with iodizing as it comes from the manufacturer without any preshrinking or additional sizing. These preliminary measures often serve to complicate matters, particularly when one is using the wet-paper process for the first time. Neverthe148

Figure 4.5 The effect of additional sizing on the negative. These two negatives were prepared, exposed, and developed identically, except that the negative on the left had no additional sizing, whereas the negative on the right was immersed in a 1 percent starch sizing solution prior to iodizing. The end result showed only the slightest gain in contrast and overall density.

Figure 4.6 The effect of whey (milk-serum) on the negative. These two negatives were prepared, exposed, and developed identically, except that the negative on the left was prepared in an iodizing solution with distilled water, whereas the negative on the right was prepared in an iodizing solution with whey. The end result showed a significant gain in contrast, as well as a noticeable color shift towards red.

less, in order to increase negative contrast, you may want to add a sizing agent to the paper over and above what has already been added by the manufacturer (see Figure 4.5). In such cases, the immersion sizing procedure given in Chapter 5 can be adapted as a preliminary step prior to iodizing the negative. The two procedures can also be combined as one, provided the sizing solution has cooled to 120°F (49°C) before adding the iodizing chemistry. For papers too fragile to stand up to the extra sizing, whey can be used instead of distilled water, according to the procedures given in Chapter 5 (see Figure 4.6). Whey increases the contrast of the negative significantly, which may be useful in making photographs during overcast conditions (see Figure 4.6). The iodizing solutions given above are adapted from original calotype practitioners. With time and practice, however, you may wish to modify these further to suit a particular mood, locale, or weather condition. Once you have found a routine that works for you, experiment by varying the amount of chemistry in solution. For example, by varying the amount of iodide, one can alter lightsensitivity and contrast. I have tried doubling the amount of iodide incrementally, from 1 to 8 percent, to find that sensitivity and con149

trast increased significantly as I moved from 1 to 4 percent. From 4 to 8 percent, however, the negative lost sensitivity and contrast due to an excess build-up of silver iodide. Another way to alter sensitivity is to vary the amount of bromide in solution. The reason for adding bromide is that silver iodide is sensitive to the violet-indigo portion of the visual spectrum, whereas the sensitivity of silver bromide extends into the blue-green portion of the visual spectrum (see Figure 4.7). By adding bromide to the iodizing solution, calotype photographers claimed to obtain better rendition of green-colored objects, like foliage. Such claims were debated and, to some extent, refuted.10 Nevertheless, I have found that adding bromide to the iodizing solution does seem to increase overall sensitivity, particularly in the shadow and foliage areas of a scene. I tried doubling the amount of potassium bromide incrementally, from 1 to 8 percent, in conjunction with a fixed 4 percent level of iodide. Between 1 to 2 percent bromide, shadow values and overall sensitivity increased up to a full stop (see Figure 4.8). At 2 percent and higher, the bromide seemed to react detrimentally with the iodide, causing loss of contrast, pinholes, and stains (see Figure 4.9).

Sensitizing Procedure

Figure 4.7 The spectral sensitivity of silver bromide and silver iodide. The column on the left represents the spectral sensitivity of silver bromide, which is shown as extending from the ultraviolet (rayons invisibles) portion of the spectrum to green-yellow (vertjaune). The column on the right represents the spectral sensitivity of silver iodide, which is shown as extending from the ultraviolet (rayons invisibles) portion of the spectrum to blue-green (bleu-vert). Reprinted from D[ésiré] v[an] Monckhoven, Traité d’optique photographique (Paris, 1866), 44, fig. 15.

150

In the wet-paper process, a light-sensitive surface is formed by floating the iodized sheet face down upon a solution containing silver nitrate and acetic acid. Sensitizing needs to be done in a darkroom under a safelight. The sensitizing solution should also be kept in a well-stopped, brown bottle, and stored in a light-tight container or dark cabinet when not in use. Stains are inevitable, so spread out several layers of newspaper upon the counter and floor space where you are working. Here it is important to bear in mind that SILVER NITRATE IS TOXIC, CAN CAUSE BLINDNESS IN COMING INTO CONTACT WITH THE EYES, AND NEEDS TO BE HANDLED WITH CARE TO AVOID STAINS ON THE SKIN. GLACIAL ACETIC ACID CAUSES MILD SKIN BURNS IN CONTACT, AND ITS FUMES ARE CORROSIVE TO LUNG AND THROAT TISSUE. WEAR AN ORGANIC-VAPOR RESPIRATOR, SAFETY GOGGLES, APRON, AND NITRILE GLOVES WHEN MIXING UP A SENSITIZING SOLUTION. WEAR AN ORGANIC-VAPOR RESPIRATOR, SAFETY GOGGLES, APRON, AND EXAMINATION GLOVES WHEN HANDLING THE PAPER IN SOLUTION. MAKE SURE THERE IS ADEQUATE VENTILATION IN THE DARKROOM WHERE YOU WORK. Never pour a sensitizing solution down the drain. Check with your local, civic authority concerning the proper disposal of a silver nitrate solution. Small, brown stains caused by silver nitrate coming into contact with your hands are perhaps inevitable, but with care, these can be kept to a minimum. They will fade away after a few days once new skin starts to form. These precautions being taken, refer to the illustration (see Figure 4.10) in following the sensitizing procedures listed below:

Figure 4.8 The effect of adding small amounts of potassium bromide to the iodizing solution. These two negatives were prepared, exposed, and developed identically, except that the negative on the left was prepared in a 4 percent potassium iodide solution with no potassium bromide added, whereas the negative on the right was prepared in a 4 percent potassium iodide solution in which 2 percent potassium bromide had been added. The end result showed a significant gain in overall density, especially noticeable in the shadow areas.

Figure 4.9 The effect of adding large amounts of potassium bromide to the iodizing solution. These two negatives were prepared, exposed, and developed identically, except that the negative on the left was prepared in a 4 percent potassium iodide solution with no potassium bromide added, whereas the negative on the right was prepared in a 4 percent potassium iodide solution in which 4 percent potassium bromide had been added. The end result showed only a slight gain in overall density, accompanied by chemical staining and numerous pinholes in the highlight areas.

1. Taking two clean sheets of glass, cut slightly larger than the iodized sheets to be sensitized (for example, 8≤ ¥ 10≤ for a 7-1/2≤ ¥ 9-1/2≤ sheet of paper), inspect them carefully under a lamp. Remove any dried chemical traces by breathing on the surfaces of the glass and wiping them gently with a soft, clean, cotton rag. Failure to take this precaution may result in small stains on the negative, caused by alkaline water deposits. 2. Set up a chemical tray and items needed for sensitizing in this area, with the two sheets of glass off to one side. 3. Take out two iodized sheets of paper and lay them upon a clean, dry surface. 151

Table 4.4

Sensitizing Solution No. 1

Distilled water at 68°F (20°C) 275 ml Silver nitrate 22 grams Glacial acetic acid 44 ml Source: [A.] Guillot-Saguez, Méthode théorique et pratique de photographie sur papier (Paris: V. Masson, 1847), 12. This solution is intended to be used in combination with iodizing solution number one (see Table 4.1). The large amount of acetic acid ensures a gradual succession of gray values in the negative and aids in preserving the white of the paper during processing. Use it for architectural, still-life, or landscape scenes that allow for extended exposure times. Cut the acetic acid level in half to obtain shorter exposure times and increase overall density. Switch to sensitizing solution number three (see Table 4.6) for lower contrast.

Table 4.5

Sensitizing Solution No. 2

Distilled water at 68°F (20°F) 300 ml Silver nitrate 28.8 grams Glacial acetic acid 18 ml Source: Adapted from a procedure attributed to Louis-Adolphe Humbert de Molard, cited in E. de Valicourt, Nouveau manuel complet de photographie sur métal, sur papier et sur verre (Paris: Librarie Encyclopédique de Roret, 1862), vol. 2, 65. This solution is intended to be used in combination with iodizing solution number two (see Table 4.2). The higher silver nitrate content, combined with a small amount of acetic acid, ensures richer blacks, shorter exposure times, and denser negatives. Double the acetic acid level if the middle and light tones of the negative seem too muddy.

Table 4.6

Sensitizing Solution No. 3

Distilled water at 68°F (20°C) 260 ml Silver nitrate 29.7 grams Glacial acetic acid 65 ml Source: Adapted from Gustave Le Gray, Traité pratique de photographie sur papier et sur verre (Paris: Germer Baillère, 1850), 7. This solution is to be used in combination with iodizing solution number three (see Table 4.3). It is similar to sensitizing solution number one (see Table 4.4), but with higher concentrations of silver nitrate and acetic acid. Cut the acetic acid level in half for shorter exposure times. Switch to sensitizing solution number one (see Table 4.4) for higher contrast.

4. Mix up one of the sensitizing solutions (see Tables 4.4 to 4.6). Always take the precaution of weakening a fresh solution by adding 27 drops of an iodizing solution. Failure to take this precaution will result in the first negative being unequally sensitized. 5. Under a safelight, pour the sensitizing solution into the tray, filtering it with a coffee filter and funnel. Level 152

A

B

C

D

E

F

G

H

I

J

Figure 4.10A, B, C, D, E, F, G, H, I, and J Sensitizing the negative. Wet-paper process. (A) Layout of the trays, film-holder, and glass sheets. (B) The position of the paper for flotation. (C) Floating the sheet of paper. (D) Lifting the paper off the sensitizer with plastic knives. (E) The sensitized paper placed upon the sheet of glass. (F) Placing the rubylith on top of the negative. (G) The second negative and sheet of glass placed on top of the rubylith. (H) Sliding the main-frame of the film-holder onto the sandwiched sheets of glass. (I) Cleaning the exterior faces of the glass with end-cap in place. (J) The film-holder with dark-slides in place ready to be loaded into the camera. Note: all of these steps are to take place under a safelight.

153

6.

7.

8.

9.

154

the trays as needed, so the solution covers the bottom of the trays entirely. Wait a few moments for any air bubbles to disappear. Taking one of the iodized sheets, float it face down upon the sensitizing solution. Flotation is achieved by grasping two opposing, diagonal corners of the paper and bowing the sheet slightly, frontside away from you, so that the diagonal thus formed comes into contact with the solution first. Follow this action by a smooth lowering of the corners being held and a gentle release upon the sensitizing solution, which aids in preventing air bubbles from forming between the surface of the paper and the solution. Papers having a tendency to curl are best controlled by quickly spreading your fingers over the backside of the paper after placing the sheet upon the solution. Once the paper starts to curl, hold your fingers in position, blocking the curling action. After a few moments, the curling tendency will start to slacken, and the rest of the process can resume. Lift the sheet once or twice as it floats, making sure there are no air bubbles trapped between the surface of the paper and the solution. Lower the paper back upon the solution as in step 6, crossing diagonals from time to time. By sliding plastic, picnic-style knives under the corners of the paper and holding the corners of the paper between the knife blades and your thumbs, the paper can be lifted more easily, keeping finger marks and paper stress to a minimum.11 Float the sheet upon the solution for a total of 1 to 5 minutes, depending on the thickness of the paper and the iodizing solution used (that is, 1 to 3 minutes for thinner papers, 3 to 5 minutes for thicker papers). In the case of paper that becomes rose-tinted after iodizing, a noticeable darkening of the backside of the paper will be observed, followed by a gradual white marbleizing, and then a complete whitening, which is an indication that the sensitizing is complete. In the case of paper that remains white and unchanged after iodizing, sensitizing is done with a stopwatch or timer, leaving the paper on the solution for 3 to 5 minutes. Keep the backside of the paper from coming into contact with the sensitizing solution, although small amounts can be removed at the end of sensitizing. Once the sheet has floated for the requisite amount of time, slowly lift it from the sensitizing solution, using the corner-and-knife method described. Allow any excess solution to drain back into the tray briefly, and transport the sensitized paper to one of the sheets of glass. Center the paper approximately; then lower it

10.

11.

12.

13.

14.

15.

16.

face down upon the glass. Lowering should be done in the same way as sensitizing, bowing the diagonal first and releasing the corners afterwards. Reposition as needed, making sure that the paper lies absolutely flat upon the glass. Repeat steps 1 through 9 with the other sheet of paper, placing it on the remaining sheet of glass. The sensitizing of two sheets at a time can also be achieved with a second tray of sensitizer. With the two sensitized sheets of paper in place, inspect the marginal areas of the glass. Wipe off any excess sensitizing solution with a paper towel. Any solution that has made its way to the backside of the paper should be removed at this time. Return the sheets of glass to where they were resting originally. Cut a sheet of rubylith film to a dimension in between the size of the glass and the paper (e.g., 7-3/4≤ ¥ 9-3/4≤), center and lower it upon the backside of one of the sensitized sheets. Next, pick up the other sheet of glass, turn it over (the paper adhering to the glass), and place it on top of the sheet with the rubylith film. The sensitized sheets should now be back to back, sandwiched between the glass, with the rubylith film in between. The rubylith film acts as a light shield between the sensitized sheets, preventing double exposure. Stand the glass sheets on end, making sure that they are aligned, and then slide them into the central groove of the main-frame of the film-holder, as indicated in Chapter 1. Once the sheets of glass are installed, make sure that the film-holder remains in an upright position to keep sensitizer seepage to a minimum. Slide the end-cap of the film-holder into position, securing the glass sheets in place. Taking a soft cotton rag, used for this purpose only, dab a small portion in some distilled water and wipe the two exterior faces of glass so as to remove excess solution and fingerprints that would otherwise cause stains. Dry the glass surfaces with a remaining portion of the rag. Having cleaned the glass, slide the two dark-slides into the outer grooves of the film-holder and the sensitizing is complete. (Repeat steps 1 though 15 if more than two sheets are to be sensitized.) Before turning on the main light source, pour the sensitizing solution back into the bottle and store it away from light. Repeated exposure of the sensitizing solution to small amounts of white light has the potential to weaken it, due to the presence of light-sensitive organic contaminants in the bottle.

155

Sensitizing Solutions: Adjustments and Fine-Tuning As seen from the sensitizing formulations, varying the amount of silver nitrate and acetic acid in solution contributes to an altering of negative density and contrast. The amount of silver nitrate in solution should be considered first, and ranges from about 8 to 12 percent. Up to a point, and dependent on the level of iodizing, an increase in silver nitrate yields an increase in overall negative density, with a decrease causing the opposite effect. Acetic acid is then considered in proportion to the silver nitrate in solution, with silver nitrate to acetic acid ratios ranging from 1 : 2 (for increased tonality) to 3 : 2 (for increased sensitivity). Bearing these relationships in mind, you might try varying the amount of silver nitrate in solution (for example, from 4 to 12 percent) in combination with different ratios of silver nitrate to acetic acid (for example, from 2 : 1 to 1 : 3) to arrive at the best combination for your specific locale or purpose. Also note that any increase or decrease of silver nitrate in solution may require a corresponding increase or decrease in the amount of iodizing (for example, from 2 to 6 percent), keeping the silver nitrate to iodide ratio about 2 : 1.

Sensitizing Solutions: Replenishment Another important factor to consider is that every sheet sensitized removes silver from the solution, gradually weakening it and simultaneously contaminating it with iodide, bromide, sizing agents, and paper fibers. This contamination can be observed in the gradual darkening of a sensitizing solution that was originally clear, as well as in splotchy patches on the negative where chemical reaction was incomplete (see Figure 4.11). Therefore, it is necessary to replenish the solution with silver nitrate from time to time, to keep the strength of the solution at an even par, and to filter it to eliminate contaminants. The following method for replenishment, originally intended for use with salt prints, has been modified for use with paper negatives:12 1. Start with about a beer bottle’s amount of sensitizing solution (330 ml) and sensitize up to eight negatives with it, keeping track of the number by marking hash-marks on a piece of masking tape adhering to the bottle. 2. After eight sheets have been sensitized, approximately 1/4 of the original volume of solution should be used up, and the remaining volume should have darkened. 3. To replenish the solution, mix up enough additional solution to top off the bottle, doubling the amount of silver nitrate that would normally be added, while keeping the acid level the same. For example, if, after sensitizing eiaght sheets with 330 ml of sensitizing solution number one (see Table 4.4), approximately 3/4 of the solution remained, the original solution would be multiplied by 0.25 to arrive 156

Figure 4.11 The result of using a weakened sensitizer. This negative was sensitized with a sensitizer that had been reused a few times without adding silver nitrate afterwards. The result was an incomplete sensitization, noticeable as light splotches on the right-hand side of the negative.

at the replenishment volume and chemical amounts. In this case, the result would be 69 ml of distilled water, to which 5.5 grams of silver nitrate and 11 ml of acetic acid would be added. To make up for the weakened state of the old solution, another 5.5 grams of silver nitrate would also be added. 4. Add this volume to the rest of the solution in the bottle, mixing the two completely. 5. To remove the discoloration, add 5 grams of kaolin (powdered china clay) to the solution and give the bottle a good shake. Allow the contents of the bottle to settle down for a few minutes in the dark. The kaolin acts like a sieve, absorbing any impurities in the solution and forcing them down to the bottom of the bottle.13 6. Once the contents have settled, the clarified and replenished solution is ready to sensitize another eight sheets. Filter it, taking care not to disturb the kaolin on the bottom of the bottle while decanting the solution. Note that there is no need to add more kaolin in subsequent replenishings of the solution. The initial amount is simply shaken up from the bottom of the bottle each time and then allowed to slowly sink back down. 157

Figure 4.12 The life span of a sensitized wet-process negative. This negative was exposed in the July heat, approximately 1 hour after sensitizing. This is just about the allowable limit for a sensitized negative in such conditions. In autumn or spring, this can be extended to up to 4 hours.

Exposing Procedure With the sensitized negatives loaded in the film-holder, you are finally in position to make exposures. And these must be made while the paper is still moist (see Figure 4.12). Keeping this in mind, it is preferable to have already decided the point of view, composition, and time of day before sensitizing the negatives. Anything that will hasten the drying out of the negatives is to be avoided as much as possible. Simple things like keeping to the shade when walking to and from the location where you are photographing, or storing the filmholder in the shadows when not in use, help to extend the sensitive life of the negative. Always keep the film-holder in a vertical, upright position until the moment of exposure to prevent the sensitizing solution from seeping behind the paper. The above precautions taken, you should have enough time to work without too much pressure because the sandwiched glass prevents evaporation. Much depends on the time of year and the given locale. Working in the Boston metropolitan area, in the heat of a summer afternoon, I have about 1 hour to make exposures before the negative dries out. Working under moderately warm conditions, in late spring and early fall, I have about 4 hours. Under moderately cold conditions, in early spring, late fall, or a winter thaw, I have most of

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the day. Some early practitioners advised lining the backside of the negatives with an additional piece of paper soaked in distilled water, claiming that it increased the moistened life of the sensitized sheets. Having tried this recommendation, I cannot encourage the practice. It results in weakened, flat negatives, and adds to the risk of staining. Since the negatives are primarily sensitive to the ultraviolet-blue portion of the spectrum, exposures should be made using natural light only. Early mornings, late afternoons, and clear, sunny days after a cold front has just passed through seem ideal times to make exposures. Slightly hazy or cloudy conditions also work if you iodize in combination with whey. Overcast and rainy days are perhaps best reserved for making positive prints, or other preliminary preparations. Exposure times are mostly affected by the amount of light involved, but other factors like the time of day, the color of the subject, and temperature play contributing roles. Generally speaking, I determine the proper exposure by taking an incident reading with a handheld lightmeter, basing my exposure upon the results of previous exposures in similar situations at the same lightmeter reading. As there is a custom quality to every negative and wide latitude for development, much remains intuitive. Nevertheless, some recommended exposure times are given in Table 4.7. Start with the shorter of the two exposure times, cutting it in half or doubling it as occasion demands.

Developing Procedure Having exposed the negatives, return to the darkroom as soon as possible to avoid letting the paper dry out. There you should have a prepared solution of gallic acid ready for use as a developer (see Tables 4.8 and 4.9), as well as a sodium thiosulfate fixing solution (see Table 4.10). Lay out four or five trays in the same area where you were sensitizing, two for development, one for a distilled water rinse, and one or two for the fixer. There you should also have two plastic knives for handling the negatives and two eye-dropper bottles, one filled with an 8 percent silver nitrate solution and the other with glacial acetic acid. TAKE THE SAME PRECAUTIONS WITH Table 4.7 Approximate Exposure Times for Paper Negatives (Incident Reading—Gossen Luna Pro) EV 19-2/3 (full, direct sunlight)

15–22 sec. @ f4

1 min.–1 min. 30 sec. @ f8

8–16 min. @ f22

EV 17-2/3 (deep shadows and bright highlights)

1 min.–1 min. 30 sec. @ f4

4–6 min. @ f8

32–40 min. @ f22

EV 18 (hazy or cloudy)

1 min.–1 min. 30 sec. @ f4

4–6 min. @ f8

32–40 min. @ f22

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Table 4.8

Working Solution of Gallic Acid

Distilled water at 85°F (30°C) 200 ml Gallic Acid 1.6 grams Source: Adapted from T. Frederick Hardwich, A Manual of Photographic Chemistry, 4th ed. (London: John Churchill, 1857), 261. This solution consists of an approximate 0.8 percent gallic acid solution. It is recommended for paper that is to be floated rather than immersed during development. Use a large beaker or tray filled with hot water to bring a smaller beaker containing the distilled water up to temperature. Then add the gallic acid, stirring until it is mostly dissolved. This solution can either be used straight or diluted 1 : 1 with distilled water for a slower development with expanded mid-range tones. Only make up enough solution for 1 day, since it oxidizes rapidly. Figure about 100 ml of working solution per negative. Filter the working solution before use.

Table 4.9

Gallic Acid Stock Solution

95% ethyl (grain) alcohol at 100°F (38°C) 75 ml Gallic acid 20 grams 95% ethyl (grain) alcohol at 100°F (38°C) to make a total volume of 100 ml Source: Adapted from a procedure attributed to William Crookes; cited in E. de Valicourt, Nouveau manuel complet de photographie sur métal, sur papier et sur verre (Paris: Librarie Encyclopédique de Roret, 1862), vol. 2, 56. This solution is an alcohol-based 20 percent stock solution, which should keep for a few months. Pour 75 ml of the alcohol into a small beaker, placing this beaker into a larger beaker or tray of hot water to bring the alcohol up to temperature. NEVER HEAT ALCOHOL DIRECTLY AS IT IS EXTREMELY FLAMMABLE. Add the gallic acid, stirring until it is mostly dissolved. Then add additional alcohol to bring the total volume up to 100 ml. Pour the solution, including any undissolved gallic acid, into a brown storage bottle and it is ready for use. Give the bottle a good shake before using. Add 2 ml of concentrate to 98 ml of distilled water for a 0.4 percent gallic acid solution. Add 4 ml of concentrate to 96 ml of distilled water for a 0.8 percent solution. Add 8 ml of concentrate to 92 ml of distilled water for a 1.6 percent solution. Filter the working solution before use.

Table 4.10 Negative Fixing Solution Distilled water at 68°F (20°C) 1000 ml Sodium thiosulfate 125 grams Source: Adapted from a procedure attributed to A[dalbert?] Cuvelier, cited in Charles Chevalier, Guide du photographe (Paris: Charles Chevalier, 1854), pt. 2, 50. Pour 1000 ml of distilled water into a beaker (or measuring cup). Add the sodium thiosulfate and stir until the chemicals are completely dissolved. As the sodium thiosulfate cools the water upon mixing, allow the solution to return to room temperature before using.

PROCESSING THE NEGATIVE AS YOU WOULD WITH SENSITIZING THE NEGATIVE. WEAR AN ORGANICVAPOR RESPIRATOR, AN APRON, SAFETY GLASSES, AND NITRILE GLOVES WHEN MIXING UP SOLUTIONS. WEAR 160

AN APRON, SAFETY GLASSES, AND EXAMINATION GLOVES WHEN PROCESSING THE NEGATIVE. 1. Fill each of the two developing trays with 100 ml of a 0.8 percent gallic acid solution (Tables 4.8 and 4.9). Level the trays as needed, so the solution covers the bottom of the trays completely. Wait a moment for any lingering air bubbles to disappear. 2. Turn off the overhead lights. All other steps are to be done under a safelight. 3. Remove the dark-slides and open up the top of the filmholder, as indicated in Chapter 1, sliding out the glass plates with the negatives in between. Carefully pry the two glass plates apart. Normally, the still-moistened negatives should remain pressed against the glass, with the sheet of rubylith film clinging to the damper of the two negatives. Lay the separated glass sheets face down so that the negatives are on top of the glass, and remove the piece of rubylith film. 4. Taking two plastic knives, slide the blades between two opposing diagonal corners of a negative and the sheet of glass, lifting the paper by pressing the corners against the blades, as done in sensitizing. 5. Transfer the negative to the first tray of developing solution. Here again, bow the paper away from you, along the diagonal not being held. Float it face down, gently releasing the corners upon the developing solution in one, smooth, continuous gesture. Lift and replace by the opposing diagonal corners once or twice to remove air bubbles. 6. Once the first negative floated for a minute and a half, start floating the second negative upon the second developing bath, repeating steps 4 and 5. 7. The negative images should start to materialize within the first 2 to 3 minutes of development. Full development is normally achieved in gallic acid alone, within 10 to 20 minutes. Developing longer than 20 minutes results in fogging. 8. If the negative seems overexposed, appearing rapidly during the first 5 minutes of development, remove it temporarily from the bath, holding it by one corner. Then, stir an eye-dropper’s worth of acetic acid into the developing solution and replace the negative. The acetic acid will slow down the action of development. Too much acetic acid results in pinholes. 9. Conversely, if the negative seems underexposed, appearing slowly during the first 10 minutes of development, remove it and stir an eyedropper’s worth of the 8 percent silver nitrate solution into the developing solution before replacing the negative. The silver nitrate speeds up the 161

10.

11.

12.

13.

14.

15.

16.

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action of development. Adding it too early results in solarized highlights. After about 5 to 10 minutes of development, lift the negatives up from the developing solution to see how they are progressing. Hold them up to a nearby safelight, viewing them by transmitted light rather than by reflected light. A properly exposed and developed negative should appear too dark when viewed by reflected light. Be careful in handling the negatives since the paper can be fragile at this stage. When a negative has begun to reach the desired state of development, fill the third tray with about 300 ml of distilled water. Once the negative reaches the desired state, transfer it to the water bath, laying it face down before immersing it completely. Follow suit with the other negative once it has reached the proper state of development, laying it face up on top of the other negative. From here, the negatives remain back to back for the rest of the procedure. Having immersed both negatives in the distilled water, occasionally agitate them by lifting up a corner of the tray. Continue to agitate for about 3 minutes, then drain the silver nitrate–laden water into an empty plastic bottle reserved for silver nitrate exhausts. Drain the darker, used gallic acid solution into this bottle as well. Do not pour these down the sink since they contain a significant amount of silver nitrate. Refill the tray with about 500 ml of distilled water, and continue to rinse the negatives for an additional 3 to 5 minutes. Drain this water down the sink, and repeat with another 500 ml of distilled water for another 3 to 5 minutes, making for a total of three distilled water changes. Once the negatives have rinsed in the distilled water, pour 500 ml of the sodium thiosulfate fixing solution (see Table 4.10) into the fourth tray. Lift successively each negative up by one corner, letting the excess water drain back into the tray, before transferring them to the fixing bath where they should be immersed back-to-back for a total of 10 minutes. Agitate the bath occasionally. After 10 minutes, the overhead lights may be turned on and the negatives are transferred to a second bath containing 500 ml of fixing solution. Fix for another 10 minutes, or until every last trace of the yellow, silver iodide precipitate is eliminated. Thicker papers may require a longer time in the fixing baths, up to 20 minutes in each bath, in combination with a stronger, 15 to 20 percent sodium thiosulfate solution. Two 500-ml baths of fixing solution should be enough to fix four negatives. Nevertheless, towards the end of the

Table 4.11 Fixer-Testing Solution (Kodak FT-1) Distilled water at 80°F (27°C) 75 ml Potassium iodide 1.9 grams Distilled water at 80°F (27°C) to make a total volume of 100 ml Source: Adapted from Eastman Kodak Company, Black-and-White Processing Using Kodak Chemicals, Kodak Publication No. J-1 (Rochester, N.Y.: Eastman Kodak, 1985), 58. Pour 75 ml of distilled water into a small beaker or measuring cup and bring to temperature by placing it in a larger beaker or tray of hot water. Add the potassium iodide and stir until dissolved. Add distilled water to make a total volume of 100 ml, pour it into an eyedropper bottle, and the solution is ready to be used. To test the first fixing bath, combine 5 drops of the fixer test solution, 5 drops of the first fixing bath, and 5 drops of distilled water. If a yellowish precipitate forms immediately (a slight milkiness is fine), the fixing bath is exhausted. To test the second fixing bath, combine 5 drops of the fixer solution, 5 drops of the second fixing bath, and 15 drops of distilled water, and look for the same yellowish precipitate. If only the first bath is exhausted, replace it with the second, mixing up fresh solution to serve as the second fixing bath.

Table 4.12 Fixer Remover Tap water at 68°F (20°C) 500 ml Sodium Sulfite 5.5 grams Source: Adapted from James Reilly, The Albumen and Salted Paper Book (Rochester, N.Y.: Light Impressions, 1980), 89. Measure the water into a beaker or measuring cup. Add the sodium sulfite and stir until completely dissolved. Pour the solution into a tray, and it is ready for use. This volume can be used with up to ten whole-plate format negatives. The solution should be used within the same day as it is mixed, and poured down the drain after you are finished.

fixing cycle, it is a good idea to check the fixing baths with a testing solution (see Table 4.11) to make sure that they have not become exhausted. Never keep a used fixer solution longer than the day you use it. Never pour a used fixer solution down the drain since it contains a large amount of silver nitrate. Pour it into a separate, empty plastic bottle dedicated to this purpose only. Label it, and when full, dispose of it in the same manner as the other exhaust bottle. DO NOT COMBINE USED FIXER WITH THE OTHER EXHAUST BOTTLE AS A NOXIOUS SULFUR DIOXIDE GAS MAY BE PRODUCED. 17. Having fixed the negatives for the requisite amount of time, transfer them to a plastic tray filled with gently running, lukewarm tap water. Wash the negatives for 3 to 4 minutes, changing the water every so often. 18. After the negatives have rinsed, immerse them for 3 to 4 minutes in a fixer removing solution (see Table 4.12). This 163

shortens the time needed for the final wash and helps to eliminate the fixer in the paper, which would otherwise cause the negative to fade. 19. Remove the negatives from the fixer removing solution and wash them for 30 to 60 minutes in gently running, lukewarm tap water, changing the water in the tray occasionally. Here it is important to make sure that the negatives are not damaged in washing. To prevent this from occurring, I use a flat, plastic dish-washing basket, similar to a papermakers’ mold. The sides of this basket are higher than the washing tray, which prevents the paper from accidentally floating out of the bath. The basket also allows the paper to be gently lifted from the bath for occasional turning, inspection, and removal. 20. After the negatives have washed for the requisite amount of time, remove one from the wash, allowing the excess water to drain off. Place it between two clean sheets of blotting paper, cut slightly larger than the format being used, and pass one of your hands over the top of the sheets to remove the excess moisture. Place the negative between two other blotters in a contact printing frame (see Chapter 5 for more on contact printing frames). Repeat this step for the other negative as well, interleaving it between two other blotters in the same contact printing frame. Close up the contact printing frame, and after a few hours, the negatives will be dry and perfectly flat. Papers with a large amount of additional sizing should be dried face up on a screen, and then flattened later with a weight, as done in iodizing. 21. Once the negatives have dried, remove them from the contact printing frame. They are ready for waxing. As a final precaution, double-check each negative to make sure there are no traces of the yellow precipitate, silver iodide. This precaution is achieved by holding a negative up to a light-source and inspecting the light areas with a loupe or magnifying glass. If there is a yellow precipitate, the negative should be refixed, either in a stronger fixing solution or for a longer period of time, then washed and dried again.

Developing Solutions: Adjustments and Fine-Tuning A solution is said to be saturated when enough of a chemical has been added to a liquid that it cannot absorb any more. Rather than dissolving, the additional amount just sinks to the bottom. Reaching saturation is difficult with gallic acid because it does not mix easily with water at room temperature. At 68°F (20°C), only about 4 grams will readily dissolve into one liter of distilled water. This amount makes for a fairly weak developing solution, which is 164

not even truly saturated. Wait several minutes, and you will be able to stir in more gallic acid. Wait a bit longer, and you will be able to add still more, making for a slow, laborious, and confusing process. The problem is simplified by raising the temperature of the water slightly. For instance, laboratory analysis has established that at 77°F (25°C), 1.16 grams of gallic acid will saturate 100 ml of distilled water.14 Raise the temperature to 90 to 100°F (32 to 38°C), and you will be able to dissolve an even larger amount, arriving at a 1.6 percent solution strength if need be. This is important to know, because original calotype photographers varied greatly in their definition of what a saturated solution of gallic acid was, citing solution strengths that varied from 0.4 to 1.6 percent. It is also important to note that a gallic acid solution is most effective between 68 to 86°F (20 to 30°C).15 On cold days, either raise the heating temperature of the darkroom or bring the developing solution up to the desired temperature, placing it in a beaker or tray of hot water. I even go so far as to use a warming tray, placing a sheet of cardboard between the developing tray and the warming surface to act as an insulating barrier and avoid heating it directly.16 Normally, with the wet-paper process, development should not be allowed to progress beyond 20 minutes, or else fogging will result. Nevertheless, by stirring in small amounts of sugar or honey into the developing solution, developing times in excess of 20 minutes may be obtained without fogging the negative.17 Yet another possibility is to accelerate the developer by adding trace amounts of ammonium acetate (see Figure 4.13). Working with

Figure 4.13 The effect of adding small amounts of ammonium acetate to the gallic acid developer. These two negatives were iodized, sensitized, and exposed identically, with only the development being different. The negative on the left was placed in a saturated, 1.6 percent gallic acid solution for about 15 minutes. The negative on the right was floated for about 2 minutes on a saturated, 1.6 percent gallic acid solution, to which a few drops of a saturated solution of ammonium acetate had been added. The negative developed with the ammonium acetate showed a significant gain in overall density. Unfortunately, however, this was coupled with a marbleized staining on the left-hand side of the negative.

165

paper iodized in ammonium iodide, rather than potassium iodide, Humbert de Molard added a few drops of a saturated ammonium acetate solution to a saturated gallic acid developing solution to dramatically reduce exposure and development times.18 Many of his contemporaries complained of the difficulties inherent in using his developing technique.19 In attempting to use it myself, I have found that it either results in a kind of marbleizing effect, or overpowers the development, darkening everything. Exposure times were cut in half at the very least, with full development being achieved in 1 minute, so it may be worth additional experimentation. Perhaps substituting sodium acetate for ammonium acetate would be better, as its action is alleged to be less vigorous.20 Sodium acetate may also work better with negatives iodized with potassium iodide than with negatives iodized with ammonium iodide. W.D. Parr made some attempts to use sodium acetate as an accelerator, adding it to the iodizing and sensitizing solutions rather than the developing solution, only to conclude that it would have been better to use it after sensitizing.21 Parr would have certainly benefited from a knowledge of Humbert de Molard’s developing procedure. From the start, it is better to develop the negatives separately, using the flotation methods as described. With practice and thin paper, however, two negatives can be immersed back-to-back during development, as done in rinsing and fixing. Developing by immersion adds a bit of intensity to the negatives, since it ensures that all of the exposed aceto-nitrate in the paper has been brought out during development. Here the alcohol-based developing solution given in Table 4.9 is to be preferred due to its penetrating action.

Clean-Up Procedure A thorough clean-up after sensitizing and developing is also an important part of the negative-making process. After making sure that all the silver nitrate–laden solutions have been poured into the proper exhaust bottles, you still have to clean the utensils, trays, and plate glass; WEARING AN APRON, SAFETY GLASSES, AND RUBBER NITRILE GLOVES, rinse everything off with running water first. For beakers and measuring cups, running water and a brief pass with a scouring pad usually suffices, and they can be stored away to dry. The dark, gray, gallo-nitrate scum that clings to the glass plates and trays needs to be removed entirely, or it will ruin future operations. Trays are effectively cleaned with water, cleanser, and a scouring pad, followed by a thorough rinsing. Glass plates require a bit more attention, however, and need to be handled carefully, to avoid either scratching it or cutting yourself on the rough edges. To clean the glass, use a spray bottle filled with white vinegar, a mild cleanser containing calcium carbonate (for example, Bon Ami), and a cotton rag kept only for this purpose. Sprinkle a small amount of cleanser on a surface of the glass, followed by a light spraying with vinegar, then thoroughly wipe the surface with the cotton rag. Repeat for the other side. Follow this cleaning with a thorough rinse in 166

Figure 4.14 Drying glass plates in the nineteenth century. This type of dish-rack is still manufactured today and is to be preferred because it allows the water to collect in one corner as it dries. Reprinted from A[lphonse] Davanne, La Photographie: traité théorique et pratique (Paris, 1888), v.1, 180, fig. 70.

running water, passing a bare hand over both surfaces of the glass to remove any alkaline, calcium carbonate deposits. Drain the sheets of glass, and place them in a dish-rack kept only for darkroom purposes until they are dry (see Figure 4.14).

Waxing Procedure Negatives should always be waxed prior to printing, for it renders the paper translucent, shortening printing time. It also improves the fineness of detail in the image, smoothing over fibers in the paper (see Figure 4.15). Yet another reason is the protective layering that results, preventing stains when the negative is placed in contact with a freshly sensitized sheet of paper, as during printing. Waxing should be done on a broad worktable, with one or two sheets of cardboard placed upon the table to protect its surface. The procedural steps for waxing a paper negative are as follows:22 1. Taking one or more large sheets of blotting paper, cut ten smaller sheets to size. These should be slightly larger than the negative paper you intend to wax, about 2≤ longer in both dimensions. 2. Pre-heat oven to 175°F (80°C). Lay two to four bars of beeswax upon an aluminum baking tray, slightly larger than the blotting paper you are using. Place the tray with the wax in the oven and wait several minutes for the wax to melt. Do not turn the temperature of the oven higher 167

Figure 4.15A and B The effect of waxing the negative. (A) A print from an unwaxed negative is coarse and grainy. (B) A print from the same negative, after being waxed, is much finer in detail and has an extended tonal range.

A

B

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3.

4.

5. 6.

7.

8.

9.

than 175°F (80°C) to hasten the process of melting; let it melt slowly. Wax is rendered useless for photographic purposes through decomposition at temperatures higher than 212°F (100°C). Once the wax has melted completely, slide two sheets of blotting paper beneath the liquid surface, pushing them down with a knife. Let these remain in the oven for a few minutes, occasionally removing the tray from the oven to turn the sheets over. Remove them from the wax by lifting up the corners of the blotting paper with a knife to avoid burning your fingertips. Return to the oven the tray containing the paper, and continue the operation until the sheets have become thoroughly saturated with wax. Once the sheets are saturated, remove the tray from the oven and rest it to one side. Taking the knife, lift up one of the corners of a sheet of blotting paper. Follow this action by quickly lifting the entire sheet up from the liquefied wax in the tray, letting the excess wax from the blotting paper drain back into the tray completely, and until all the excess wax on the blotter has hardened and cooled. This cooling should only take a few moments. Repeat this step with the other saturated sheet of blotting paper. Both the wax in the tray and the saturated blotters can be reheated endlessly. Repeat steps 3 and 4, saturating a total of six sheets of blotting paper with wax. At the worktable, turn on an electric iron and set its heat control to a low-medium setting (for example, rayon or polyester-cotton blend). The iron should be used for this purpose only. Avoid using the steam setting. Any preexistent water should be thoroughly drained from the iron’s reservoir as well. Taking three of the saturated sheets of blotting paper, lay them neatly in a pile on the cardboard covering the worktable. Next, lay an unwaxed negative on top of the pile, centering it, followed by the remaining three sheets of saturated blotting paper. Holding the stack of paper in place with one hand, begin ironing the topmost sheet. Ironing should be done slowly, evenly, in a circular motion. Continue ironing for a while, occasionally checking the results within the sandwiched sheets. With time and repeated applications of the iron, the wax in the blotter paper should start to liquefy, gradually saturating the negative with wax and making it translucent. Make sure that the same face of the topmost sheet of blotting paper always comes into contact with the iron since the iron leaves metal traces on the surface. Once the negative is thoroughly saturated with wax, lift it up by one corner and let it cool for a moment. Place it to one side, apart from the saturated blotters. 169

10. Take two of the unwaxed sheets of blotting paper and place them in a pile, apart from the ironing area with the saturated blotters. Place the recently waxed negative on top of the unwaxed blotters, centering it; then add the two remaining, unwaxed blotters. 11. Holding the sheets down by one edge with one hand, begin ironing once again with a circular motion, again making sure that the same face of the topmost sheet always comes in to contact with the iron. Continue to iron the negative, checking it occasionally, until all of the excess wax has been removed. This is recognized by the gradual disappearance of the slightly shiny, mottled surface of excess wax, which is replaced by a duller, more even surface. At this stage, the negative is perfectly waxed and ready for printing. 12. Store the negative in a mylar, polyethylene, or glassine envelope when not in use (see the appendix listing for sources of archival storage envelopes).

THE DRY, WAXED-PAPER PROCESS The dry, waxed-paper process was originally developed by Gustave Le Gray, around 1850, and represents a modification of the wet-paper process. The materials, chemicals, and techniques used in making the negative are quite similar in both processes, chief differences being that with the dry, waxed-paper process, the paper is waxed before starting any chemical operations, and the negative is dried prior to exposing it. The paper is also left in the chemical solutions for a longer period of time to give the chemistry time to penetrate the wax and reach the paper fibers. The dry, waxed-paper process offers an advantage over the wet-paper process in that the negatives can be exposed for up to a few days after sensitizing, making short trips to more distant locations possible. One drawback is that the dry exposed negative is less light-sensitive, necessitating longer exposure times. Grain is also more noticeable, which produces coarser details (see Figure 4.16). I have opted for Alphonse Davanne’s later modification of Le Gray’s procedure because it omits potassium fluoride and the highly toxic potassium cyanide, which were viewed as superfluous by later practitioners.

Waxing Procedure Except for a few minor points, the procedural steps for waxing paper for the dry, waxed-paper process are identical to those used in the wet-paper process. Refer to the procedural steps given for the wetpaper process, noting the following changes: 1. Waxing takes place as a preliminary step. Cut the paper to size, marking a marginal area of the backside prior to waxing to identify it during subsequent operations. 170

Figure 4.16 A dry, waxed-paper negative. This negative was exposed dry, approximately 18 hours after sensitizing. The process greatly increases the life-span of the sensitized negative, but it also has more grain than would have been the case with a wetprocess negative.

2. Up to six sheets of paper may be waxed at one time, stacked together, between saturated sheets of blotting paper. Simply turn the sheets over from time to time until all have absorbed the wax from the blotters. 3. With white paper, it is difficult to see how evenly the surface has been waxed. Holding the white, waxed sheets over a dark surface will make viewing easier. 4. Additional ironing of the waxed paper takes place after iodizing, and again after the negative has been processed and dried. 5. Due to the preliminary waxing, any folding or creasing of the paper during subsequent operations will result in a permanent mark that will appear on the positive.

Iodizing Procedure Iodizing for the dry, waxed-paper process is similar to the wetpaper process, except for the amount of time involved. Whey and lactose are added to increase contrast and help the iodizing solution penetrate the waxed sheets more easily. Once again, iodizing is done 171

Table 4.13 Iodizing Solution No. 4 Whey at 68°F (20°C) 500 ml Potassium iodide 7.5 grams Potassium bromide 1 gram Lactose 10 grams Source: Adapted from a procedure attributed to Gustave Le Gray; cited in A[lphonse] Davanne, La Photographie: traité théorique et pratique (Paris: Gauthier-Villers, 1888), vol. 1, 441. This formula should be used within the first 2 days of its preparation. A procedure for making whey is given in Chapter 5. Stored in dry conditions, paper iodized with this solution should keep several months.

Table 4.14 Iodizing Solution No. 5 0.5% potato starch solution at 68°F (20°C) 1000 ml Lactose 45 grams Potassium iodide 15 grams Potassium bromide 2 grams Source: Adapted from a procedure attributed to Gustave Le Gray; cited in A[lphonse] Davanne, La Photographie: traité théorique et pratique (Paris: Gauthier-Villers, 1888), vol. 1, 442. This formula should be used within a few days of its preparation. See Chapter 5 for more on how to make a starch sizing solution. Allow the solution to cool to at least 120°F (49°C) before adding the iodizing chemistry. Stored in dry conditions, paper iodized with this solution should keep several months.

under ordinary room-light, either in the darkroom sink or a bathtub. The violet, iodide stains that result from the paper drippings are water soluble and easily removed. ALWAYS WEAR AN ORGANICVAPOR RESPIRATOR, AN APRON, AND NITRILE GLOVES WHEN MIXING UP IODIZING SOLUTIONS. ALWAYS WEAR AN APRON AND SURGICAL-TYPE GLOVES WHEN HANDLING THE PAPER IN SOLUTION. Clean up thoroughly after you have finished. Solutions may be disposed of by pouring them down the drain. 1. Cut a dozen sheets of paper to size (for example, 8-3/4≤ ¥ 11-3/4≤ for a final 210 mm ¥ 270 mm negative), waxing them in the manner described above. 2. Mix up an iodizing solution (Tables 4.13 to 4.14). Note that these iodizing solutions should be used within 1 to 2 days of their preparation, due to the presence of whey and lactose. 3. Pour the iodizing solution into a tray, filtering it with a few folds of fine linen to remove foreign debris, which might otherwise stain the negative. Wait a few moments for any lingering air bubbles to disappear.

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4. Taking one sheet of paper at a time, hold it by two adjacent corners and completely immerse it in the iodizing solution. Remove any air bubbles that form on either side of the paper. Turn it over once, twice, and, when the sheet is thoroughly wetted and face down again (1 to 2 minutes later), introduce the next sheet on top of this one, repeating the step for a maximum of twelve sheets. 5. After the last sheet has been immersed and wetted, agitate the tray briefly and leave the paper remaining in the iodizing solution for 2 hours. Check the bath at 15-minute intervals, agitating it and rotating the sheets occasionally to make sure that no air bubbles are trapped in between the sheets of paper. 6. After 2 hours have passed, turn the entire stack of paper over. Hang a sheet up to dry by one corner, using a line and clothespin. Position the paper so that it does not collapse upon itself when drying, as done in the wet-paper process. Repeat for all other sheets in the iodizing solution. 7. After each sheet has been hanging a few moments, place a small piece of paper in the lowest hanging corner of each sheet to absorb the excess solution that collects there. Failure to take this precaution will result in a small, concentrated area of iodide, causing a small silver iodide stain on the negative. Repeat steps 1 through 7 if more than twelve sheets are to be iodized. 8. Leave sheets to hang for a few hours until they are completely dry. Because of the weak iodizing solution, most papers will appear almost unchanged afterwards. 9. Once the paper has dried, remove it from the line and re-iron it, as indicated below. Stored in an archival box, away from excessively humid conditions, the iodized sheets should keep for several months.

Restoring the Wax Once the iodized sheets have dried, they should appear less transparent, as though they have returned to their original state prior to waxing. To restore the preservative function of the wax and to prevent the sensitizing solution from penetrating too deeply into the paper, it is necessary to re-iron the iodized sheets. Iron them one at a time, between four sheets of unwaxed blotting paper, making sure that the temperature of the iron is set no higher than the rayon or polyester-cotton blend setting, to avoid decomposing the wax. Pass the iron over the blotters for a few moments, then check each sheet under a lamp, making sure that no shiny spots of wax remain. When ready, the sheets should appear transparent again, as they did prior to iodizing.

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Sensitizing Procedure Sensitizing the negative using the dry, waxed-paper process differs from the wet-paper process, in that the iodized sheets are immersed up to three at a time, one on top of the other, rather than floated one by one. The main problem with this is that trapped air bubbles may lead to incomplete sensitizing at times (see Figure 4.17). Lay out newspaper upon the counter where you work, along with two plastic knives and four trays. Remember that SILVER NITRATE IS TOXIC, CAN CAUSE BLINDNESS WHEN COMING INTO CONTACT WITH THE EYES, AND NEEDS TO BE HANDLED WITH CARE TO PREVENT STAINS ON THE SKIN. GLACIAL ACETIC ACID CAUSES MILD SKIN BURNS, AND ITS FUMES ARE CORROSIVE TO LUNG AND THROAT TISSUE. WEAR AN ORGANIC-VAPOR RESPIRATOR, SAFETY GOGGLES, A PROTECTIVE APRON, AND NITRILE GLOVES WHEN MIXING UP A SENSITIZING SOLUTION. WEAR AN ORGANIC-VAPOR RESPIRATOR, SAFETY GOGGLES, A PROTECTIVE APRON, AND SURGICAL-TYPE GLOVES WHEN HANDLING THE PAPER IN SOLUTION. MAKE SURE THERE IS ADEQUATE VENTILATION IN THE DARKROOM

Figure 4.17 The effect of trapped air bubbles in sensitizing. In the upper part of this negative, small, white spots are noticeable. These are the result of air bubbles remaining on the negative during sensitizing.

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Table 4.15 Sensitizing Solution No. 4 Distilled water at 68°F (20°C) 300 ml Silver nitrate 21 grams Glacial acetic acid 27 ml Source: Adapted from a procedure attributed to Gustave Le Gray; cited in A[lphonse] Davanne, La Photographie: traité théorique et pratique (Paris: Gauthier-Villers, 1888), vol. 1, 443. This solution is intended to be used in combination with iodizing solution nos. 4 and 5 (see Tables 4.13 and 4.14). Always take the precaution of weakening a fresh solution by adding 27 drops of a 1.5 percent solution of potassium iodide. If you fail to take this precaution, the first negative will be unequally sensitized.

WHERE YOU ARE WORKING. These precautions being taken, sensitizing proceeds as follows: 1. Mix up the sensitizing solution (see Table 4.15). This solution will last indefinitely, and can be replenished in the same way as the sensitizing solutions for the wet-paper process. 2. Pour the solution into the first tray, filtering it to remove foreign debris that might otherwise stain the negative. Wait a few moments for any lingering air bubbles to disappear. Fill each of the remaining three trays with 500 ml of distilled water. 3. Taking one sheet of paper at a time, hold it by two adjacent corners and completely immerse it in the sensitizing solution. Remove any air bubbles that form on either side of the paper with a plastic knife. Turn it over once, twice, and, when the sheet is thoroughly wetted and face down again (1 to 2 minutes later) introduce the next sheet on top of this one, repeating for a maximum of three sheets. 4. Once the last sheet has been immersed and wetted, agitate the sheets occasionally, checking for air bubbles, turning and rotating them until the first sheet has remained in the sensitizing solution for 15 minutes. 5. After 15 minutes, turn the entire stack of paper over. The first sheet should now rest on top, face up. Lift it up by one corner, allowing the excess solution to drain back into the tray for a few moments. Then immerse the sheet face down into the first bath of distilled water. Follow suit with the remaining sheets, introducing them into the distilled water bath at intervals 1 to 2 minutes apart. Agitate the tray of distilled water from time to time, making sure that no air bubbles are trapped in between the sheets. 6. After 10 to 15 minutes in the first distilled water bath, turn the entire stack of paper over. Transfer the sheets one by one, in exactly the same manner, to the second and third 175

distilled water baths. Let the sheets remain there for a total of 10 to 15 minutes per bath. 7. After 10 to 15 minutes in the third distilled water bath, turn the entire stack of paper over one last time. The first sheet should again rest on top, face up. Lift it up by one corner, allowing the solution to drain back into the tray, then lay it between two, dry sheets of blotting paper, cut slightly larger than the negative format being used. Rub your hand over the top of the blotting paper to remove the excess moisture, then transfer the dampened, sensitized sheet between two other pieces of blotting paper kept in a contact printing frame. 8. Repeat step 7 with the remaining sensitized sheets until they are all interleaved between blotters in the contact printing frame. Close up the contact printing-frame and store it in a light-tight bag. In this way, the negatives will be perfectly flat once they are dry. Repeat steps 1 through 8 if more than three sheets are to be sensitized. Clean-up procedures are identical to those outlined under the wet-paper process. Return the sensitizer to the bottle and empty the other trays as soon as you have finished. Note that the water from the first distilled water rinse should not be poured down the sink. Pour it into the bottle reserved for silver nitrate exhausts.

Exposing Procedure It is best to expose the paper within 24 hours of sensitizing to ensure reliability and consistency. Under dry weather conditions, the sensitized sheets may be exposed up to 3 to 7 days later. Prior to exposure, a sheet of Luan is loaded into the dry, waxed-paper film-holder and the sensitized sheets are taped to it (see Chapter 1 for more on the design of the film-holder). Next, the end-cap is slid into the filmholder along with the dark slides. Apart from the loading of the filmholder, all other steps involved in exposure are identical to those of the wet-paper process, except that the exposure times are a bit longer. Use the longer of the two exposure times given in Table 4.7 as a starting point. Halve or double these as need be. Note: a wet-paper process film-holder can be used with the dry, waxed-paper process as well, the steps involved in loading the sensitized sheets being identical to those of the wet-paper process.

Developing Procedure Development should take place within the same day as exposure, or, at the latest, the next day. This involves immersion for 1 to 2 hours in 300 ml of a 0.5 percent gallic acid solution at 68 to 86°F (20 to 30°C). Refer to the alcohol-based concentrate given under the wet-paper process (see Table 4.9) for more on how to make up the 176

solution. A maximum of two negatives should be developed in a tray at one time, back to back. Use two developing trays placed side-byside if you are planning to develop four at a time. Lay out a tray for the distilled water rinse, and another one to two trays for the fixer. Except for the length of developing time and strength of the fixing solution, steps involved in processing, washing, and drying the negative are identical to the wet-paper process. Take the same precautions when processing the negative as you would with sensitizing the negative. WEAR AN ORGANIC-VAPOR RESPIRATOR, AN APRON, SAFETY GLASSES, AND NITRILE GLOVES WHEN MIXING UP SOLUTIONS. WEAR AN APRON, SAFETY GLASSES, AND SURGICAL GLOVES WHEN HANDLING THE NEGATIVES IN SOLUTION. Here are a few specifics to bear in mind when processing dry, waxed paper negatives:

• Be very careful in handling the negatives in solution, as they •

•

•

• •

• •

are already waxed. The slightest folding of the paper will leave a crease that is impossible to remove. Stir in one or two eyedroppers’ worth of 8 percent silver nitrate solution into the gallic acid, just before beginning development, to account for the loss of excess silver nitrate in the negative that was removed in rinsing the sheets after sensitizing. Development proceeds very slowly at first, with the image only starting to appear after several minutes in the developer. After the first 15 minutes of constant agitation, feel free to leave the negatives resting in the tray for up to two hours, returning to the darkroom at 15-minute intervals to turn the negatives over and check on how development is progressing. If the image appears overexposed, appearing quickly within the first 30 minutes of development, stir in one or two eyedroppers’ worth of glacial, acetic acid to slow down the process of development. Development should not be carried out much longer than 2 hours, as fogging will result. Use two 500 ml baths of a 20 percent sodium thiosulfate solution as a fixer. Leave the negatives in each bath for 10 to 15 minutes, checking the fixer at the end of the operation, as done with the wet-paper process. Rinse, fix, remove, and wash the negatives as done with the wet-paper process, drying the negatives between blotting paper in a contact printing frame as well. Once the negative has dried, it should be ironed one last time to prevent details from being too coarse upon printing.

In concluding this section on the dry, waxed-paper negative, it may be worthwhile to quote Thomas Keith, a Scottish calotypist who used a variant of the dry, waxed-paper process in the 1850s, and 177

who described the density of improperly exposed negatives in the following way: Failures from underexposure speak for themselves; those arising from overexposure are very curious, and at first sight very puzzling. Pictures overexposed generally come up rapidly in the gallic acid and appear to be all right, till on examining them by transmitted light, they are seen to have a reddish gray appearance all over, and the high lights are not deeper than the half tints.23

NOTES 1. Two contemporary descriptions of the calotype process are to be found in Richard Morris, “Calotype Negatives,” in Coming into Focus: A StepBy-Step Guide to Alternative Photographic Printing Processes, Ed. John Barnier (San Francisco: Chronicle Books, 2000), 17–25; and Jan Arnow, Handbook of Alternative Photographic Processes (New York: Van Nostrand Reinhold, 1982), 39–45. In both cases, the process described is essentially the same, characterized by what was originally termed doubleiodide of silver. This involves a preliminary step using silver nitrate, followed by iodizing, and a mixture of gallic acid and silver nitrate, which serves as a sensitizer. Unfortunately, the gallic acid in the sensitizer quickly decomposes in combination with the silver nitrate, often ruining the negative prior to exposure. 2. For more on safety concerns in using photographic chemistry, see Susan Shaw and Monona Rossol, Overexposure: Health Hazards in Photography, 2nd ed. (New York: Allworth Press, 1991); and Siegfried and Wolfgang Rempel, Health Hazards for Photographers (New York: Lyons and Burford, 1992). 3. For more about contemporary paper production, see Silvie Turner, Which Paper?: A Review of Fine Papers for Artists, Craftspeople and Designers (London: Estamp, 1991). 4. Mid-nineteenth-century recommendations concerning calotype paper negative thickness may be found in D[ésiré] van Monckhoven, Méthodes simplifiées de photographie sur papier (Paris: Marion, 1857), 25; Gustave Le Gray, Traité pratique de photographie sur papier et sur verre (Paris: Germer Baillière, 1850), 3; and Charles Chevalier, Guide du photographe (Paris: Charles Chevalier, 1854), pt. 2, 46. Monckhoven wrote that the paper should weigh 7 to 10 kg (15 to 22 lb.) per ream. Le Gray wrote that the paper should weigh 6 to 12 kg (13 to 26 lb.) per ream, with thinner papers being used for portraits and thicker papers for landscapes. Chevalier quoted a calotypist named A[dalbert?] Cuvelier, who specified that the paper should weigh 7 kg (15 lb.) per ream for portraits and 12 to 15 kg (26 to 33 lb.) per ream for landscapes using the wet-paper process, and 4 to 5 kg (9 to 11 lb.) per ream using the dry, waxed-paper process. 5. Guillot-Saguez’s wet-paper process is given in A. Guillot-Saguez, Méthode théorique et pratique de photographie sur papier (Paris: V. Masson, 1847). For biographical information about A. Guillot-Saguez, see André Jammes and Eugenia Parry Janis, The Art of French Calotype (Princeton, N.J., Princeton University Press, 1983), 185–187.

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6. Le Gray’s wet-paper process is given in Gustave Le Gray, Traité pratique de photographie sur papier et sur verre (Paris: Germer Baillère, 1850), 4–17. For biographical information about Le Gray, see Eugenia Parry Janis, The Photography of Gustave Le Gray (Chicago: Art Institute of Chicago, 1987); and Jammes and Janis, French Calotype, 200–205. 7. Humbert de Molard’s procedure is given in E. de Valicourt, Nouveau manuel complet de photographie sur métal, sur papier et sur verre (Paris: Librarie Encyclopédique de Roret, 1862), vol. 2, 65–68. For biographical information about Humbert de Molard, see Jammes and Janis, French Calotype, 191–193. 8. For more on Baldus, see Malcolm McDaniel, The Photography of Édouard Baldus (New York: The Metropolitan Museum of Art, 1994); and Jammes and Janis, French Calotype, 139–142. 9. An alleged account of Flacheron’s procedure is given in Robert Hunt, A Manual of Photography (1853; reprint, New York: Arno, 1973), 233–236. For biographical information about Flacheron, see Jammes and Janis, French Calotype, 179–180. 10. Adding bromide to iodizing solutions is discussed in T. Frederick Hardwich, A Manual of Photographic Chemistry, 4th ed. (London: John Churchill, 1857), 63–66. I would like to thank Joel Snyder of the University of Chicago for bringing this book to my attention. 11. The use of plastic knives for handling paper has been modified from Le Gray, Traité pratique, 7. Le Gray used ivory knives instead of plastic. 12. This method of replenishment has been adapted from James Reilly, The Albumen and Salted Paper Book (Rochester, N.Y.: Light Impressions, 1980), 60. 13. For more on kaolin, see Thomas Sutton, A Dictionary of Photography (London: Sampson Low, 1858), 242. 14. The saturation level for gallic acid is to be found in Charles D. Hodgman, ed., Handbook of Chemistry and Physics, 36th ed. (Cleveland: Chemical Rubber Publishing, 1954), 940–941. 15. The temperature of gallic acid during development is discussed in Monckhoven, Méthodes simplifiées, 49–56. 16. On the subject of warming gallic acid for development, I am indebted to Mark Osterman of the George Eastman House for suggesting the use of a warming tray. 17. Once again, for the suggestion to add sugar as a restrainer to the gallic acid solution, I am indebted to Mark Osterman, who adapted this practice from his experience in using the wet-collodion process. 18. For the details of Humbert de Molard’s developing procedure, see Valicourt, Nouveau manuel, v.2, 66–68. 19. Complaints against the use of ammonium acetate as an accelerator in development can be found in Gustave Le Gray, Nouveau traité théorique et pratique de photographie sur papier et sur verre (Paris: Lerebours et Secretan, 1851), 124–125; and H[enry] H[unt] Snelling, A Dictionary of the Photographic Art (1854; reprint, New York: Arno, 1979), 2. 20. Substitution of different acetates was suggested in [C.L.] Barreswil and [Alphonse] Davanne, Chimie photographique, 3rd ed. (Paris: Mallet-Bachelier, 1861), 394. 21. For more on Parr’s use of sodium acetate, see W.D. Parr, “On the Use of Acetate of Soda as an Accelerator,” Journal of the Photographic Society, No. 43 (June 21, 1856), 65–66.

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22. This waxing procedure has been adapted from a procedure attributed to Le Gray; cited in A[lphonse] Davanne, La Photographie: traité théorique et pratique (Paris: Gauthier-Villars, 1888), vol. 1, 440. 23. Thomas Keith, “Dr. Keith’s Paper on the Waxed Paper Process,” Photographic Notes, vol. 1, no. 8 ( July 17, 1856): 104.

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5 Salt Prints by Development Having acquired an understanding of the procedures involved in making paper negatives, you are now in position to apply these procedures to making positive prints. With regard to photographs made during the calotype era, one usually has in mind a positive technique known as salt printing. Salt printing received its name from one of the chemical ingredients, sodium chloride, or common table salt. Most early salt prints were made by a process known as printing-out, whereby a positive image was made by laying the negative face down upon another sensitized sheet of paper and exposing the sandwiched combination directly to sunlight until an image was formed.1 By the 1850s, another kind of salt-printing process existed, in which the positive image could be made through a combination of sunlight and chemical development. This method was known as developing-out. Largely overlooked today, but in many ways preferable, salt printing by development deserves more attention. Although the large majority of salt prints from paper negatives were made by printing-out, it is also true that a great number of developed-out salt prints were made in the 1850s. Having worked with both methods, I have decided to provide detailed instructions for salt printing by development for a number of important reasons:2

• The relatively rapid fading and discoloration of printedout salt prints was well known to the first photographers. Properly processed developed-out salt prints are far more stable than the printed-out variety, and have, on average, withstood the test of time far better than the printed-out variety. • Most modern photo-historians and practicing photographers are unaware that printing out a calotype paper negative in the sun, even on a very bright, sunny day, can take 2 or more hours to reach completion. This means that on cloudy days, or with the 6 or 7 hours of available daylight in winter, it is often impossible to print-out a negative completely. In comparison, developed-out salt prints only require 181

• •

• • •

exposures ranging from a few seconds to a few minutes, even on cloudy days or in winter. Developed-out salt prints are no less authentic printing processes to the 1850s than printed-out salt prints. The amount of silver nitrate in solution needed to make a successful printed-out salt print is usually greater than the amount needed to make a comparable developed-out print. This holds true for noble metal compounds like gold chloride, which can be used in developed-out printing, but are not absolutely necessary to improve or change the tone. In other words, developing-out is significantly less expensive than printing-out with salted paper. The range of controls for achieving a desired contrast or hue in a developed-out salt print is far greater than in a printed-out salt print. Developed-out prints can be processed to look exactly like printed-out prints made from the same negative. Developed-out printing shares many analogies with contemporary black-and-white darkroom printing and may be viewed as its original precursor.

Having stated my reasons for choosing developing-out, I should now explain why developing-out processes have been overlooked. One reason is because the vast majority of calotype photographers made salt prints by printing-out rather than developing-out. Nevertheless, a perusal through an important British photographic journal of the period, Photographic Notes, covering the years 1856 to 1862, yields no less than seventeen relevant passages concerning “printing by development.” One finds many of the journal’s readercorrespondents and even its editor, Thomas Sutton, actively encouraging fellow photographers to adopt “printing by development,” in preference to printing-out, or, what was then termed, “sun-printing.” One reader summed up his experience of developing-out in the following way: “The development is a beautiful operation, the picture seems to spring out. I like printing now as much as I detested it before, for it is not a mechanical process as the common [printed-out] method is, but one which requires judgment and skill to conduct properly.”3 Developing-out has also been overlooked because it has received an unwarranted reputation for yielding coldly neutral tones. Such a view is exemplified in the writings of Helmut Gernsheim, a photohistorian whose perspective on the technological development of photography remain highly influential to this day. For Gernsheim, developing-out was an industrial, mass-scale application of saltprinting technology. He linked it to the business acumen of the French photographer Louis-Désiré Blanquart-Évrard, who founded a photographic printing factory in Lille, France, in the early 1850s.4 Concerning the qualities of Blanquart-Evrard’s developed-out prints, Gernsheim wrote, “They have preserved their cold dark grey colour to this day, but most of the prints are too dark and lacking in 182

contrast. [. . .] Neither the colour nor the quality of the prints can compare in beauty with the warm reddish-brown colour of the [printed-out] calotype prints produced by Hill and Adamson.”5 As an illustration of this, see the color-plate section of the book. There you will find a reproduction of a Maxime Du Camp print made by Blanquart-Évrard in 1850 (Color Plate I). The print is characteristic of the kind of neutral tone that Gernsheim ascribes to developingout. Compare this with the reproduction of an untoned Hill and Adamson salt print from the mid-1840s, which is typical of the warm tone that Gernsheim ascribes to printing-out (Color Plate II). While aware of the business connection that existed between Blanquart-Évrard and Thomas Sutton in the mid to late 1850s, Gernsheim chose to relegate Sutton to a subordinate role, rather than view him as a pioneer of developing-out processes in his own right. Simply put, Gernsheim would have us believe that Sutton served as a kind of spy for Prince Albert, who was seeking to obtain the details of Blanquart-Évrard’s industrial-printing process, in order to divulge them to the world. Thus, according to the logical extension of Gernsheim’s view, getting back at Blanquart-Évrard for having stolen Talbot’s original, patented calotype procedures and making them public in France. Eventually, Sutton lured Blanquart-Évrard into a business partnership, whereupon Blanquart-Évrard revealed the details of his process. Since he was legally tied to the business alliance, Sutton could only make Blanquard-Évrard’s printing process public once the carbon-printing process had rendered it obsolete.6 Unfortunately, it is this view of developing-out that still holds sway among today’s photo-historians, curators, and conservators, when they describe the characteristics of mid-nineteenth-century developed-out prints.7 What follows is a revision of this view. Rather than emphasizing the developing-out procedures of BlanquartÉvrard, considered solely with regard to their applications to industrial printing, we will devote ourselves to the developing-out procedures of Thomas Sutton, put forth here as the progenitor of a more custom, or individualized, approach. Here it may be useful to cite a few of Sutton’s own remarks on the subject. Concerning printed-out salt prints, he writes: They possess no richness and vigour, unless they are bedaubed with albumen, and in that state they can be compared to nothing that has yet been considered beautiful. . . . In sun-printing the picture is entirely superficial. A darkened surface of chloride protects the sensitive matter beneath from the action of light, and this, which has merely served as a support to the other, is afterwards washed out in the baths, and generally goes down the sink. . . . 95 per cent of the silver is lost this way.8

Concerning developing-out, he writes: “The objection that developed prints are inferior to the others is untenable. The process which can produce a sharp and beautifully modulated negative can also by repetition produce a sharp and beautifully modulated posi183

tive.”9 Ultimately, he declares, “The photographer who reads this . . . will perceive at a glance that I have abandoned the method of sun-printing in favor of that by development.”10 Sutton’s remarks date to the years 1855 to 1856, shortly after he had associated himself with Blanquart-Évrard. If Sutton’s own remarks are to be trusted, we may look at any print he made shortly after 1855 to see how the tonalities of his developing-out process compare with those of Blanquart-Évrard and Hill and Adamson. In the color-plate section of the book is a reproduction of a print by Sutton dating to 1856, when he alleges to have switched to developing-out processes (Color Plate III). Here the tonality is much warmer than in the Du Camp/Blanquart-Évrard print, more in line with the qualities Gernsheim ascribes to printing-out. As a further confirmation of this, see an untoned developing-out print I made using one of Sutton’s developing-out procedures (Color Plate IV ). Once again, the tonality is a warm, chocolate brown, not a neutral or cold tone. In short, the modern perception of mid-nineteenth-century developing-out techniques necessarily yielding neutral or cold tones needs reevaluation. The procedures for making a developed-out salt print are similar to those used in making negatives with the wet-paper process. The first stage is known as salting. The paper is floated upon a solution of either sodium or ammonium chloride, to which additional sizing agents and citrates may be added; then it is dried. The second stage is known as sensitizing. The salted sheet is floated upon a solution of silver nitrate and either citric or acetic acid, whereby the silver unites with the chloride in the paper to form the light-sensitive silver chloride. After the paper has dried a second time, in a light-tight place, a negative is laid down face to face upon the sensitized sheet, and the two are placed in a contact printing frame and exposed to daylight. After exposure, the print is removed from the contact printing frame, a faint image now being visible. Next, it is floated upon a gallic acid developer until the image has been brought out completely. Development is followed by a water rinse, fixing, and a final water wash, as was the case in making paper negatives. In addition to the developed-out salt print, a variant procedure known as the serum-process will be presented. The serum process is similar to the dry, waxed-paper negative process, and involves the immersion of the paper in a bath containing milk-serum, or whey, instead of a salting solution. Once the paper has dried, it is immersed in a sensitizing solution containing silver nitrate and acetic acid, then dried and exposed in a manner identical to developed-out salt printing. Next follows an immersion development, a salt-water rinse, an optional toning stage, fixing, and the final water wash.

CHEMICALS NEEDED Many of the chemicals used to make salt prints are the same as those needed to make paper negatives. The following are re184

quired and may be obtained from the chemical suppliers listed in the appendix:

• • • • • • • •

Sodium chloride Ammonium chloride Sodium citrate Silver nitrate Glacial acetic acid Citric acid Gallic acid Sodium thiosulfate

The following chemicals are not absolutely essential, although they may prove useful in fine-tuning certain desired effects:

• Sodium acetate • Gold chloride • Potassium iodide The following ingredients are also necessary, and may be obtained from supermarkets, health-food stores, and art-supply stores:

• Distilled water (suggested for every step, excepting the final water wash) Potato or arrowroot starch Gelatin (hard) Skim milk (1 percent milk-fat) Liquid rennet (used to coagulate milk) Lemons Calcium carbonate–based cleanser (Bon Ami“ is a good commercial substitute) • White vinegar • Kaolin (powdered china clay)

• • • • • •

Note: as was the case with paper negatives, in making salt prints, the practitioner will be exposed to certain chemicals and acids that demand a requisite amount of protection from bodily harm. Neither the author nor the publisher takes any responsibility for injury or loss that may arise from using the materials and procedures described. It is the reader’s responsibility to insure that his or her workplace is safe, well ventilated, and that he or she is wearing the proper protective covering for a given chemical or procedural operation. Rubber nitrile or examination gloves, a plastic apron, an organic-vapor respirator, and safety goggles are to be worn as occasion demands. Request a Material Safety Data Sheet (MSDS) in ordering any chemical (chemical manufacturers or distributors must supply these upon request). Read it and be thoroughly familiar with each chemical’s properties prior to beginning any chemical operation. Follow the sequence of the procedural steps as indicated. 185

MATERIALS NEEDED Most of the materials needed to make salt prints are the same as those used in making paper negatives. Refer to the materials needed list in Chapter 4 for a more detailed description. In addition to these, the following items will be needed:

• Four to eight sheets of single strength, window-pane glass for sensitizing (for example, 9≤ ¥ 11-1/2≤ for an 8-1/2≤ ¥ 11≤ piece of paper) • Four to eight shot-glasses (identically sized to support the glass plate during sensitizing) • An eyedropper • One 100 ml eyedropper bottle One item that may be difficult to obtain is a contact printing frame (see Figure 5.1). Locations can be found in the appendix. These come in a number of different formats, so choose one that is slightly larger than the negatives you intend to use (for example, 11≤ ¥ 14≤ for an 8-1/2≤ ¥ 6-1/2≤ whole-plate negative contact printed onto an 8-1/2≤ ¥ 11≤ piece of paper). Sometimes it is necessary to line the back of the contact printing frame with black felt or thin, black foam, to ensure flush contact between the negative and the print. A possible substitute to a contact printing frame was suggested by Charles Fabre in 1890.11 This involved sandwiching the negative and positive paper between three pieces of glass, held together by two belts with clips on each end (see Figure 5.2). Pressure was obtained by tightening the belts from behind. This system is easily realized.

Figure 5.1 A nineteenth-century contact printing frame. This type of split-back contact printing frame is still manufactured today and allows the progress of exposure to be checked by opening up one section of the back, without moving the negative or print. Reprinted from Charles Fabre, Traité encyclopédique de photographie (Paris, 1890), v.3, 43, fig. 511.

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Figure 5.2 An alternative to contact printing frames. Reprinted from Charles Fabre, Traité encyclopédique de photographie (Paris, 1890), v.3, 44, figs. 513–15.

Ask a glass retailer to cut three 1/4≤-wide pieces of glass, one being 11≤ ¥ 14≤ and the other two being 7≤ ¥ 11≤ each, taking the extra precaution of having the edges of the glass smoothed. Rig up a belt system similar to the diagram, attaching metal clips with a 1/2≤-wide opening to the ends of two, 1≤-wide belts. The large sheet of glass is placed in front of the negative and positive, the two sheets behind, with the system being held in place by the two belts. Here it would also be helpful to line the back of the paper with a 11≤ ¥ 14≤ piece of thin, dense foam. In order to inspect the print after exposing, remove one of the belts, along with one of the smaller sheets of glass; this avoids disturbing the registration of the negative and positive print. As was the case with paper negatives, selecting the right kind of paper for positives is one of the most crucial decisions you have to make. Today, many alternative process photographers prefer thick artist’s papers in making their prints. I prefer thinner papers, between 24 to 32 lb., and in this preference I believe I am in keeping with the practices of mid-nineteenth-century photographers, who usually printed on paper thin enough to be pasted into an album. If you are printing from a whole-plate dimension negative, or smaller, finding thin paper is not a problem since office stationery cut to the standard 8-1/2≤ ¥ 11≤ format is readily available. If you are intending to print larger, you will have to order uncut office stationery, known as flatsheets, directly from a paper distributor. Locations for paper distributors are in the “Sources of Supply” appendix listing. The criteria for choosing a good positive paper are quite similar to those for choosing negative papers, except here we are concerned with the image as viewed by reflectance, rather than transmittance. Therefore, watermarks and screen markings are not as much of an issue. Ideally, paper selected for printing should be 100 percent cotton, have a neutral pH and good wet-strength, and not curl when wet. The color of the paper should also be considered, particularly for the tone it imparts to the highlights. Normally, I use plain white paper, but with higher contrast negatives, I sometimes use a “natural” or “antique” white paper, which helps to soften the highlights. As was the case with paper negatives, it is important to avoid archival papers containing alkaline buffers since they cause spontaneous overdevelopment.

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The following papers are recommended for making salt prints by development and can be found in most office stationery and artsupply stores:

• Southworth“ Resumé (24 lb.). Readily available in 8-1/2≤ ¥ 11≤ and 8-1/2≤ ¥ 14≤ formats, in both White (R14CF and 34E) and Ivory (R14ICF and 34IE), this is a favorite paper. It has a superb wet-strength and does not curl. It also stands up to additional sizing quite well. Handle Southworth paper only in the margins, or staining will result. Southworth also makes a thinner (20 lb.) paper (13C and 33E), which works equally well. • Crane“ Business and Legal Papers (24 lb.). These encompass a number of papers: Florescent Bright White (BB811S), Natural White (BB816S), and Ivory (BL816S). All of them have a nice texture and work well. A significant amount of sizing is added in the manufacturing, which makes printing without additional sizing a possibility. Wetstrength and curling could be better, although they are not serious problems. The off-white color selection is a plus with Crane papers. • Crane“ Kid Finish or Premium Presentation Papers (32 lb.). Available in Pearl White (BK801S) and Ecru White (BK 806S), these slightly thicker papers also have a significant amount of sizing added in the manufacturing, which makes printing without additional sizing a possibility. Wet-strength and curling tendencies are improved over the thinner (24 lb.) Crane papers, although more silver is absorbed by the thicker paper. • Bienfang“ 360 (13.5 lb.) or Borden & Riley“ 100R (13.5 lb.) Marker Papers. For those wanting an even thinner paper, these are suggested. Additional sizing should be kept to a minimum, however, as they are very fragile and have a poor wet-strength (see Chapter 4 for how to wash and dry thin papers). They are especially recommended for the serum-process, which involves sensitizing by immersion. Given the necessary chemical ingredients and materials, the following standard has been assumed for the procedures that follow. Normal paper refers to papers weighing 24 to 32 lb. per ream and thin paper refers to those weighing 13.5 lb. per ream. Paper is cut into 8-1/2≤ ¥ 11≤ sheets to print a whole-plate sized negative, and marked on the backside with an “X” (or other suitable notation) so as to distinguish it from the frontside during subsequent operations. Plate glass refers to single thickness, window-pane glass, cut to 9≤ ¥ 111/2≤ for sensitizing and developing purposes. Trays are 10-1/2≤ ¥ 15≤ Pyrex“ baking trays. Other format sizes may certainly be used instead of these, just remember to make the necessary adjustments concerning the dimensions of the glass plates and trays involved, and 188

to increase or decrease the volumetric amounts of chemical solutions as occasion demands.

SALT PROCESSES The following section concerns developing-out salt processes devised by Thomas Sutton and Frederick Hardwich in the 1850s.12 Each process involves an initial salting stage, followed by a sensitizing stage, then a visual examination of the print during exposure, and finally, developing and processing. Sizing, salting, sensitizing, and developing are all achieved through flotation rather than immersion. Depending on the amount of sizing involved, prints obtained from these processes can either have a matte surface or a slight sheen. They range in tone from warm-brown, to sepia, to cold neutral-gray. Before moving to the salting stage, it is important to determine whether the paper needs additional sizing. Sizing is a kind of glue that is added to the paper to keep chemistry from sinking in too deeply. It also contributes to the contrast and brilliance of the print. By holding a sheet of paper up to a light and examining the surface sheen of the paper, you can get an idea as to how heavily sized it is. Most office stationery has already been sized by the manufacturer to some extent, in order to keep ink on the surface. Therefore, it may be better to use office stationery for the first time without additional sizing, since this step adds an extra set of complications from the start. This advice being taken, it should be added that the sizing given by a manufacturer is often not enough for photographic purposes. In such cases, the paper requires additional sizing to keep the prints from appearing too sunken-in, or flat in contrast, and sizing becomes an essential part of the printing process. Sizing formulations generally divide into two camps, gelatin or starch. Gelatin is made from animal hides and bones, and yields colder, neutral-gray tones. Starch is made from plants, and yields warmer, brownish-purple gray tones. English papers from the midnineteenth century were usually sized with gelatin, whereas French papers from the same era were usually sized with starch. Since all of the papers recommended for salt printing are sized with starch by the manufacturers, I tend to add starch sizing rather than gelatin. Nevertheless, one salting solution given in the chapter does use gelatin for those interested in this possibility (see Table 5.3). Do not reuse a sizing solution after you have finished a given session. Pour it down the drain, followed by hot running water.

Sizing Procedure: Flotation Listed below is a starch-sizing procedure, using flotation. It yields a smooth, satin-like sheen on one side of the paper. Note that the 1 percent starch solution given here is intended for 24 to 32 lb. papers. For thinner papers, use a 0.5 percent starch solution. Time of flotation should also be decreased to 2 to 3 minutes for thinner papers. 189

Refer to the illustration (see Figure 5.3), in relation to the following procedural steps: 1. Cut a dozen (or more) sheets of paper to size, leaving ample margin areas for handling. Make a small mark on one corner of each sheet’s backside in order to distinguish it from the frontside during subsequent operations. 2. Measure out 900 ml of distilled water. Pour this volume into an enamelware pot, cover with a lid, and begin to heat the water to a boil. 3. While the water is heating, weigh out 10 grams of potato or arrowroot starch. Pour the starch into about 75 ml of distilled water, stirring it to break up the clumps. Add a little more distilled water, bringing the total volume up to 100 ml. Stir again, and let the starch settle. 4. Once the larger volume of distilled water has come to a rolling boil, uncover the pot completely. Stir up the settled starch in the smaller volume of distilled water, making sure that it is completely distributed. Then pour it into the boiling water, stirring continuously with a wooden spoon. The water should transform into a glutinous solution almost immediately. 5. Reduce the heat to a moderate boil and continue stirring the solution to distribute the starch before lumps occur. Continue to boil 3 to 4 minutes longer, stirring constantly; then remove the pot from the heat. 6. Pour the sizing solution into an enamelware tray, slightly larger than the paper you intend to use. Let the solution cool uncovered. 7. Turning on the faucet of a large sink or tub, allow the running water to reach the hottest possible temperature without scalding. Fill a large plastic tray with the hot water, then turn off the running water. 8. Lower the enamelware tray into the plastic tray with the hot water, taking care not to splash any water into the sizing solution. Let the displaced water fall back into the sink or tub, continuing to lower the enamelware tray until it can be released. 9. Once the sizing solution has cooled a bit, slide a glass thermometer beneath its surface and leave it there, resting horizontally. Let the solution continue to cool, checking its temperature occasionally. 10. Once the sizing solution has cooled to 115°F (47°C), start to float one of the sheets of paper. Flotation is achieved by grasping two diagonal corners of the paper and bowing it slightly, with the frontside away from you, so that the bowed diagonal thus formed comes into contact with the solution first. This action is followed by a smooth lowering of the corners being held, and then a gentle

190

11.

12.

13.

14.

15. 16.

release upon the sizing solution, which is to be accomplished in a continuous motion to drive away air bubbles between the surfaces of the paper and sizing solution. Note: two sheets may be floated at the same time by doubling the amount of sizing solution and floating the paper in two separate trays. Let the paper rest upon the solution for a total of 5 minutes, lifting it up occasionally and then lowering it back down in the manner just described. Cross the diagonals from time to time, using the other opposing diagonal corners to drive away air bubbles. Sliding plastic, picnicstyle knives under the corners instead of your index fingers will help keep markings on the frontside to a minimum. Poke any persistent air bubbles with the knives. After 5 minutes of flotation, partially lift the sheet by the closest two corners. Then drag the sized surface across the closest edge of the enamelware tray to remove excess sizing. Transfer the paper to a sheet of glass lying on a nearby table, laying it upon the glass with the sized surface facing up. Take a squeegee and gently remove the excess sizing from the paper’s surface. This removal is accomplished in two stages. First, remove about a 1/2≤ of excess sizing from one of the edges of the paper. Then, moving in the opposite direction, remove the excess size from the rest of the surface, starting from within the 1/2≤ margin of paper you cleared away first. In this way, the sizing solution is thinly and evenly distributed across the front surface of the paper. In using the squeegee, do not bear down on the paper. Use it in a very light and even-handed manner, allowing just the weight of the squeegee to rest upon the paper in pulling it across. Dry the paper face up on a screen, or hang to dry by one corner using a line and clothespin. If hanging to dry, let the paper rest horizontally on the glass sheet for a moment to allow the sizing to spread out equally. Once the sheet is hanging to dry, place a small piece of paper in the lowest corner to absorb any excess solution that collects there. Remove the excess sizing from the glass with the squeegee and wipe off the squeegee. Repeat steps 1 through 15 for the other sheets of paper, making sure that the temperature of the sizing solution does not fall below 95°F (35°C). When it reaches this point (usually after six sheets), remove the sizing tray from the water tray, refill the plastic tray with hot water, and then lower the sizing tray upon the larger tray once again. Within moments, the sizing solution will be back up to 115°F (47°C), and the sizing procedure can resume.

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A

D

B

E

C

F

Figure 5.3A, B, C, D, E, F, and G Different stages in flotation sizing. (A) The sizing tray placed in a larger tray of hot water. (B) Lowering a sheet of paper upon the solution by opposite diagonal corners. (C) Lifting the paper off the solution using plastic knives. (D) The final removal of the paper by dragging it across the edge of the tray. (E) Removing excess sizing with a squeegee. (F) Hanging the paper up to dry by one corner. (G) The paper hanging to dry with a small piece of paper placed at the lowest hanging corner to absorb excess solution.

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G

17. After all the sheets have been sized, pour the sizing solution down the drain. 18. Rinse off the sizing utensils with warm water. Note: in hanging sheets of paper to dry by one corner, any resultant unevenness can be remedied by sizing a second time, and hanging the sheets to dry by the opposite corner. Passing the squeegee in a direction perpendicular to the first also helps to remedy unevenness, as does thinning the sizing solution.

Sizing Procedure: Immersion Listed below is a starch-sizing procedure using immersion. It yields a less brilliant luster than flotation, but it is quicker and easier to use. Be sure to handle the paper by the corners and margins, otherwise finger marks are sure to result. Also note that the 1 percent starch solution given here is intended for 24 to 32 lb. papers. For thinner papers, use a thinner, 0.5 percent starch solution. Time of immersion is 5 to 10 minutes in both cases. The procedure is as follows:

1. Cut and mark the backsides of the paper, as done with flotation sizing. 2. Make a 1 percent starch sizing solution, as done with flotation sizing. 3. Pour the warm sizing solution into an enamelware tray and allow to cool, checking its temperature from time to time with a glass thermometer, as done with flotation sizing. 4. Once temperature has cooled to 115°F (47°C), take a sheet of paper by two adjacent corners and slide as much of the sheet as possible beneath the surface of the sizing solution. Turn it over, pushing down any part of the paper not wetted with a wooden spoon. 5. Repeat steps 1 through 4 with up to six sheets of paper, watching for trapped air bubbles and pushing down any areas not wetted with a wooden spoon. 6. 5 to 10 minutes later, or once the sixth sheet has been thoroughly wetted, turn the entire package over so that the frontside of the first sheet is now facing you. Turn this sheet over one last time and remove it from the sizing solution. 7. Lay the paper upon a thick sheet of glass, with the frontside facing the glass. Squeegee the excess sizing solution off the backside of the paper in two stages. First, starting about 1≤ from the top of the paper, apply a moderate amount of pressure with the squeegee, dragging it across the rest of the backside of the paper. Next, lift the sheet by one corner and squeegee the excess solution off the glass. Turn the paper upside-down, again with the frontside facing the glass, and squeegee the backside of the paper in the same manner once again. In this way, the sizing will be equally distributed throughout the paper. 8. Hang the paper to dry by one corner using a line and clothespin. 9. Repeat steps 6 through 8 with the remaining sheets of paper, making sure that each sheet remains in the sizing bath for an equal amount of time. 10. Once all six sheets are hanging, place a small piece of paper in the lowest hanging corner to absorb the excess sizing solution that collects there. Note: any resultant unevenness may be remedied by sizing a second time and hanging the sheets to dry by the opposite corner. 11. Repeat steps 1 through 10 if six more sheets are to be sized, making sure that the temperature of the solution remains between 95 to 115°F (35–47°C), as done in flotation sizing. 12. After all the sheets have been sized, pour the sizing solution down the drain. 13. Rinse off the sizing utensils with warm water. 193

Salting Procedure The steps involved in salting a sheet of paper are very similar to those of iodizing a negative. Most of the older formulations call for either floating or immersing the paper. Since I have found that immersion causes stains on the backside, I always float the paper to minimize this tendency. The salting solutions given here should not pose any health risks; still, it is a good idea to wear surgical gloves and an apron to keep fingerprints and clothing stains to a minimum. Clean up thoroughly after you have finished. Solutions may be disposed by pouring down the drain. Salting proceeds as follows: 1. If salting without additional sizing, cut a dozen sheets of paper to size, and mark a marginal area of the backside of each sheet with a soft pencil. The mark is to distinguish it from the frontside during subsequent operations. Other relevant marginal notations (for example, paper type, chemicals used, date, and so on) may be included here as well. 2. Mix up a salting solution (see Tables 5.1 to 5.3). 3. Pour the salting solution into a tray, filtering it with a coffee filter and funnel. Wait a few moments for any lingering air bubbles to disappear. 4. Begin floating one of the sheets of paper in the same manner as given for flotation sizing. Note: two sheets may be floated at the same time by doubling the amount of salting solution and floating them in separate trays. 5. Let the paper rest upon the solution for a total of 5 minutes, lifting it occasionally and lowering it back down in the manner described for flotation sizing. Poke any persistent air bubbles that cling to the paper with a plastic knife. 6. Once the sheet has floated for 5 minutes, lift it slowly from the surface of the solution so as to minimize any dripping tendency. Hang to dry by one corner with a clothespin. After the sheet has been hanging to dry for a few moments, place a small strip of paper in the lowest hanging corner, to absorb the excess solution that collects there. Failure to take this precaution will result in a small, concentrated area of chloride, causing a small, silver chloride stain in the corner of the print. (Repeat steps 1 through 6 for all other sheets to be salted.) 7. After all the sheets have been salted, pour the salting solution down the drain. 8. Rinse off the salting utensils with warm water. 9. Leave sheets hanging for a few hours until they are completely dry. 10. Once the paper has dried, remove it from the line and flatten it by sandwiching the curled sheets of paper between two clean sheets of mat-board. Stack the paper 194

so that the salted surfaces are face to face, and place a heavy weight on top of the pile for a few hours to flatten them. Upon removal, the salted sheets are ready for sensitizing. Stored face to face in an archival box, away from excessively humid conditions, they should keep several months.

Salting Solutions: Adjustments and Fine-Tuning The salting solutions given here range in concentration from about 1 to 6 percent. Since stronger salting solutions combined with stronger sensitizing solutions yield deeper blacks than weaker ones (most easily observed in the margins rather than the image itself ) it might be interesting to halve or double the salting solutions, keeping the respective sensitizing solutions the same, to see how changing the salting strength affects the resulting image. Table 5.1

Salting Solution No. 1

Distilled water 500 ml Sodium chloride 33.3 grams Freshly squeezed lemon juice 33 to 50 drops Source: Adapted from a procedure attributed to Thomas Sutton; cited in E. de Valicourt, Nouveau manuel complet de photographie sur métal, sur papier, et sur verre (Paris: Librairie Enyclopédique de Roret, 1862), vol. 2, 209. This is a strong, 6 percent salting solution to be used in combination with sensitizing solution no. 1 (see Table 5.4). Use it to obtain intense blacks, with mid-tones ranging from russet brown to sepia, depending on the exposure and development time (Color Plate V). The solution can be used only for a few days, on account of organic ingredients in the lemon juice. Cut the lemon with a plastic knife. If you use a metal one, the print will be blackened and ruined. Filter the solution before use.

Table 5.2

Salting Solution No. 2

Distilled water 500 ml Sodium chloride 10 to 15 grams Freshly squeezed lemon juice 39 to 59 drops Source: Adapted from Thomas Sutton, “On an Improved Process of Printing by Development without a Toning Bath,” Photographic Notes, 2nd ed., vol. 3, no. 42 ( Jan. 1, 1858): 10. This is an economical, 2 percent salting solution to be used in combination with sensitizing solution no. 2 (see Table 5.5). The varying amounts of salt and lemon juice are to adjust the print contrast, with the lesser amounts yielding more contrast than the stronger amounts (corresponding to similar changes in the sensitizing bath). Print tones range from a russet brown to deep sepia. This solution should be used only within a few days of its preparation, on account of the lemon juice. Cut the lemon with a plastic knife, not a metal one, or the print will be blackened and ruined. Filter the solution before use.

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Table 5.3

Salting Solution No. 3

Distilled water 500 ml Gelatin (hard) 2.3 grams Ammonium chloride 5.7 grams Sodium citrate 5.7 grams Source: Adapted from T. Frederick Hardwich, A Manual of Photographic Chemistry, 4th ed. (London: John Churchill, 1857), 246 and 260. This is a combined sizing and salting solution to be used in combination with sensitizing solution no. 3. Use it to obtain prints with tones ranging from a reddish split-tone to a colder, neutral, slate gray (Color Plate VI). To mix it up with the solution and salt paper, use the following procedure: 1. Cut a dozen sheets of paper to size, marking them in the margin with an “X” or other suitable notation. No other preliminary sizing is needed since it is to be done at this time. 2. Stir 2.3 grams of gelatin into 500 ml of distilled water at room temperature. Let this solution stand 15 minutes, stirring occasionally. 3. Once the gelatin has swollen, warm the solution to 120°F (49°C). Warming is most easily accomplished by pouring the solution into an enamelware tray, filtering it through a few folds of fine muslin, and then placing the enamelware tray into a larger tray of hot water, as described in the procedure for flotation sizing. When the solution has warmed to the proper temperature, stir in 5.7 grams ammonium chloride, followed by 5.7 grams sodium citrate. Once the chemicals have dissolved, leave the solution at 120°F (49°C) for an additional 15 minutes, stirring occasionally. Do not raise the temperature of gelatin higher than 130°F (54°C), or it will decompose. 4. Allow the solution to rest for about 15 minutes. At this point, it should be smooth, without lumps or noticeable congelation. 5. Taking one of the sheets of paper by two opposing diagonal corners, start to float it face down in the manner described for flotation sizing. 6. Float the paper for a minute and a half, lifting the paper once or twice by the opposite diagonal corners and then replacing it upon the surface of the solution so as to drive away air bubbles. 7. After a minute and a half, slowly lift the sheet by one corner and allow the excess solution to drain back into the tray for a moment. Hang the sheet to dry by one corner using the clothespin and line method. After a few moments, attach a small piece of paper to the lowest hanging corner to absorb the excess solution that would otherwise collect there. 8. Repeat steps 5 through 7 for as many sheets as you plan to salt, making sure that the temperature of the salting bath remains between 95 to 115°F (35 to 47°C). 9. Pour out the solution once the salting session is over. 10. Rinse off the salting utensils with warm water.

Sodium chloride solutions yield warmer image tones than ammonium chloride solutions. Therefore, it might be interesting to see how substituting ammonium chloride for sodium chloride affects the resulting image tone, and vice versa. (Substitute 4 parts ammonium chloride for 5 parts sodium chloride.) Another possibility would be to add other chemical traces to a salting solution. For example, 196

instead of straight sodium chloride, I like to use unrefined French sea salt, which can be bought from a specialty grocer. It yields a slightly cooler tone and richer blacks than straight sodium chloride (Color Plate VII). The composition of sea salt being given as 4 parts sodium chloride to 1 part magnesium chloride, I initially was of the opinion that it was the magnesium chloride that contributed to the colder tones.13 Looking at the sea salt, however, I noticed that it is of a slightly blue color, perhaps an indication of iodine. Since iodized negatives tend to be more neutral in tone than sodium chloride salt prints, it might be interesting to add very small amounts (that is, 0.25 to 0.5 percent) of potassium iodide to a salting solution, or try iodized salt instead of straight sodium chloride, to see how print tonality is affected. According to Sutton, “by adding a little iodide of potassium to the salt, the paper is rendered much more sensitive and the print more permanent, its colour is also improved by an admixture of grey or blue; but the process is less manageable and certain.”14 Many contemporary salting formulations call for sizing and salting to be combined as one solution, thus eliminating an extra step. I have instead found that adding salting chemistry to the sizing solution diminishes the effect of the sizing. Therefore, I have treated separately sizing and salting procedures, with one exception (see Table 5.3). By operating in two stages, I find the sizing to be more effective in acting as a barrier to suspend the chemicals above the paper, which as a result increases the overall contrast and brilliance. For economy of time, however, you may prefer to combine the two stages as one. In this case, try doubling the amount of starch normally used when sizing and salting separately, since the addition of the salt will weaken the action of the sizing. Use the flotation procedure described for salting solution number three (see Table 5.3) as a model for combining the other sizing and salting solutions. Filter these thicker solutions with a few folds of fine muslin, rather than filter paper. Another possibility would be to substitute gelatin for starch as a sizing agent to see how tonality and contrast are effected. Size and salt separately, starting with a 1 percent gelatin sizing solution, following the mixing procedures outlined in salting solution number three (see Table 5.3). Then follow the procedures outlined earlier for either flotation or immersion sizing.

Sensitizing Procedure Sensitizing salt prints is essentially the same as sensitizing negatives using the wet-paper process. Sensitizing should be done under a safelight, following either of the two methods described below. ALWAYS TAKE THE NECESSARY SAFETY PRECAUTIONS IN WORKING WITH SILVER NITRATE. WEAR SAFETY GOGGLES, EXAMINATION GLOVES, AND AN APRON. MAKE SURE THAT YOUR DARKROOM IS ADEQUATELY VENTILATED, OR WEAR AN ORGANIC-VAPOR RESPIRATOR, PARTICULARLY WHEN MIXING UP A SOLUTION. 197

The first method is to pour all of the sensitizing solution into a tray (see Tables 5.4 through 5.6), filtering it, and to float a salted sheet face down for 2 to 3 minutes, following the steps outlined for sensitizing negatives with the wet-paper process (see Chapter 4). To prevent the sheets from being unequally sensitized, a freshly made sensitizer is first weakened by adding twenty-seven drops of a sodium chloride solution, the strength matching that originally used to salt the paper (for example, 2 percent for a 2 percent salting solution). After eight sheets have been sensitized, follow the steps given for purifying and replenishing a sensitizing solution in Chapter 4, and the sensitizer can be used again and again. Weakened sensitizing solutions may be used to advantage with negatives high in contrast (Color Plate VIII). The second method consists in pouring a small amount of fresh sensitizer (for example, 40 ml for every 8-1/2≤ ¥ 11≤ sheet of salted paper) onto a leveled sheet of plate glass. The glass is cut slightly larger than the paper being used (for example, 9≤ ¥ 11-1/2≤ ) and is suspended above a Pyrex tray by four identical glasses (see Figure 5.4). The solution is spread out over the sheet of glass by means of the edge of a long strip of paper, and the salted sheet floated face down for 2 to 3 minutes, following the methods outlined for sensitizing a negative with the wet-paper process (see Chapter 4). Once the sensitized paper is hanging to dry, the solution on the glass is drained into the Pyrex tray, and the sheet of glass is flipped over, allowing another piece of paper to be sensitized on the other side with another 40 ml of sensitizing solution. In this way, up to eight prints can be identically sensitized using four sheets of glass. When the sensitizing session is over, the solution accumulated in the tray is poured back into the bottle, and the ordinary means of replenishment and purifying are applied (see Chapter 4). Note: this method of sensitizing may also be used to advantage with wet-process paper negatives. Once the salted paper has been sensitized by either of the two methods, it needs to dry in a darkened room. It needs to dry completely, or else the negative will be stained in coming into contact with it during exposure. In hanging the sensitized sheet up to dry, hang it by the opposite corner of the one used for salting, attaching a small piece of paper to the lowest corner to absorb any excess solution. Failure to take this precaution results in a diagonal staining (Color Plate IX). If you slowly remove the sheet from the sensitizing solution, drips of silver nitrate falling to the floor are kept to a minimum.15 Spread some newspaper or a drop-cloth on the floor to prevent stains from occurring anyway. Once the sensitized paper has dried, it is ready for use. Ideally, exposure and processing should take place within 24 hours after sensitizing, although the sensitized sheets can be used up to 2 to 3 days later in dry conditions. I usually sensitize four to eight sheets in the evening, allow them to dry overnight, and expose and process them during the next day. Store the dried sheets in a light-tight box or in the kind of black plastic bag in which most commercial photo paper

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A

B

C Figure 5.4A, B, C, D, E, and F Flotation sensitizing using a sheet of glass. (A) Leveling a sheet of glass above a glass tray by means of four small glasses. (B) Pouring a small volume of sensitizer upon the sheet of glass. (C) Spreading the sensitizer out by means of a strip of paper. (D) Lowering the salted sheet of paper upon the sensitizer. (E) Lifting the sensitized sheet off the glass, using plastic knives. (F) The sheet of paper hanging to dry by one corner, with a small piece of paper placed at the lowest hanging corner to prevent staining. Note: all of these steps are to take place under a safelight.

D

F E

is packaged, laying the sensitized surfaces face to face to avoid staining the backsides. Avoid touching the sensitized surfaces in handling the paper, or fingerprints will result.

Sensitizing Solutions: Adjustments and Fine-Tuning The sensitizing solutions given below range in strength from approximately 7 to 17 percent silver nitrate. Considered in combination with the salting solution being used, they represent ratios varying from 2.5 to 3.75 parts silver nitrate to 1 part sodium or ammonium chloride. Keeping these ratios in mind, one could experiment with silver nitrate to chloride ratios, varying them from 2 to 4 parts silver nitrate to 1 part chloride, to see which yields the best result. As given in sensitizer no. 2 (see Table 5.5), lemon juice can be substituted for saturated citric acid in a sensitizer formulation, with

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Table 5.4

Print Sensitizing Solution No. 1

Distilled water 300 ml Silver nitrate 40 to 50 grams Citric acid (saturated solution) 12 to 16 ml Source: Adapted from a procedure attributed to Thomas Sutton; cited in E. de Valicourt, Nouveau manuel complet de photographie sur métal, sur papier, et sur verre (Paris: Librairie Enyclopédique de Roret, 1862), vol. 2, 210. This solution is to be used in combination with salting solution no. 1 (see Table 5.1). It represents a 13 to 17 percent silver nitrate solution to be adjusted in relation to the amount of lemon juice used in the salting bath. Filter before use. To make a saturated solution of citric acid, add 66.5 grams of citric acid to 50 ml of distilled water at room temperature. Store the citric acid solution in a 100 ml stoppered bottle.

Table 5.5

Print Sensitizing Solution No. 2

Distilled water 300 ml Silver nitrate 22.5 to 33.8 grams Citric acid (saturated solution) 6.3 to 9.5 ml or Lemon juice 5.6 to 8.5 ml Source: Adapted from Thomas Sutton, “On an Improved Process of Printing by Development without a Toning Bath,” Photographic Notes, 2nd ed., vol. 3, no. 42 ( January 1, 1858): 10. This solution is to be used in combination with salting solution no. 2 (see Table 5.2). It represents a 7 to 12 percent silver nitrate solution to be adjusted according to the strength of the salting bath. Use saturated citric acid (see Table 5.4) to obtain a warm image, with very clean, white highlights, or switch to lemon juice for cooler warm tones, with muted, light-gray highlights. Stir to dissolve any precipitate and filter before use. Note: if lemon juice is to be used, the leveled plate glass method of sensitizing should be adopted; add the lemon juice just before sensitizing, on account of decomposition.

Table 5.6

Print Sensitizing Solution No. 3

Distilled water 300 ml Silver nitrate 20.5 grams Glacial acetic acid 19.5 ml Source: Adapted from T. Frederick Hardwich, A Manual of Photographic Chemistry, 4th ed. (London: John Churchill, 1857), 260. This solution is to be used in combination with salting solution no. 3 (see Table 5.3). It represents a 7 percent silver nitrate solution. Exposing longer and reducing development time achieves a red-neutral “split” effect, while exposing less and increasing development time achieves straightforward neutral-gray tones.

the result being a slightly cooler tonality with muted highlights. One could combine lemon juice with saturated citric acid in varying proportions to fine-tune this effect. Figure the amount of saturated citric acid needed first, then multiply this volume by 0.89 to arrive at the replacement volume of lemon juice. 200

Exposing Procedure In the darkroom, under a safelight, lay the negative face to face with the sensitized sheet in a contact printing frame. The glass of the contact printing frame should be clean, without any scratches or fingerprints. In closing the contact printing frame, make sure that the negative is adequately centered, resting on top of the sensitized sheet when viewed through the glass. In most cases, it should appear laterally corrected, although reversing the left-right orientation of a negative on thin paper is possible. Placing a sheet of thin black foam or black felt between the back of the contact printing frame and the sensitized sheet helps to ensure that full contact is achieved with the negative. Cover the glass of the contact printing frame with a piece of cardboard before removing it from the darkroom so as not to expose the paper prematurely in transit. Exposure should take place from an open window, preferably facing north, away from direct sunlight. Any kind of daylight will do, under any kind of weather condition: sunny, cloudy, or rainy. I prefer to print on dull, gray days, reserving sunny days for making negatives. On sunny days, one key to consistency is to orient your printing frame so that it is facing the highest point in the sky, approximately 66 to 90° away from the sun. This ensures the richest, most constant source of ultra-violet light. Exposure is determined by visual inspection; usually 30 seconds to 4 minutes of exposure will suffice on sunny days, whereas cloudy days will demand anywhere from 4 to 20 minutes. A general inspection of the print consists of watching the border area surrounding the negative, which should slowly turn from white, to a very light shade of lilac, to a middle-gray value lavender. Usually, the border area should not be allowed to darken much more than this. A more specific inspection consists of occasionally removing the printing frame from daylight, covering it, and opening up a section of the split-back frame in the darkroom to view part of the print under a safelight. One continues the exposure, checking and rechecking in this way, until a faint image is visible upon the printing paper with partially defined shadows and middle tones, and as yet undefined, key highlights. Quite a bit of latitude is allowable in exposing the print. Overexposure is compensated by developing for less time, whereas underexposure is compensated by developing longer. Similarly, if the negative is flat in contrast, expose less and develop longer for more contrast. Conversely, if the negative has too much contrast, expose longer and develop less for a flatter effect. The result will be a colder print in the former case and a warmer print in the latter. Use of a test-strip and an artificial UV exposing unit, along the lines of contemporary black-and-white printing practices, might be used in the hopes of obtaining an exact level of control and consistency, but there is really no need for such extremes.16 One quickly acquires an experienced eye for visual inspection using daylight after the first few attempts. 201

Developing Procedure Once the print has been exposed for the requisite amount of time, it is removed from the contact printing frame and developed. Development can either take place immediately after exposure or later the same day, storing a number of exposed prints away, face to face in a light-tight container. Print processing is very similar to negative processing and is conducted as follows: 1. Under a safelight, lay out four to five Pyrex trays and develop the print by flotation upon 100 ml of developing solution. Two prints may be developed simultaneously using separate trays. With salting and sensitizer combination no. 1 (see Tables 5.1 and 5.4), use a 1.6 percent gallic acid solution. With salting and sensitizer combinations nos. 2 and 3 (see Tables 5.2 and 5.5, or Tables 5.3 and 5.6), use a 0.8 percent gallic acid solution. See Chapter 4 for more on how to mix up a gallic acid solution. 2. Develop from 6 to 20 minutes with salting and sensitizer combination nos. 1 and 2 (see Tables 5.1 and 5.4, or Tables 5.2 and 5.5). Develop from 3 to 7 minutes with salting and sensitizer combination no. 3 (see Tables 5.3 and 5.6). In printing, it is best to keep the developer at room temperature, checking the progress of development from time to time by carefully lifting the print off the developer and viewing it by reflected light. Note: when printing under a safelight, you may turn on a dim incandescent bulb for a few moments to regard the print at varying stages of development. Either a 40-watt incandescent bulb or a 60-watt yellow bug-light will work fine, kept at a distance of about 7 feet.17 The paper is not nearly as light-sensitive as conventional, black-and-white photographic paper. 3. Generally speaking, develop until the print has reached the desired density. Prints exposed longer and developed less (for warmer tonalities and less contrast) should be developed until they are just a shade darker than the desired end result, since they bleach slightly in the subsequent baths. Prints exposed less and developed longer (for cooler tonalities and more contrast) should be stopped at the exact point where print density looks best, since they do not bleach afterwards. 4. Once the print has reached the desired state, transfer it to another tray containing 300 to 500 ml of distilled water, immersing it for about 3 to 5 minutes. If another print is to be developed at the same time, the first print is held in the water bath until the second print is ready to be added to it, whereupon they remain back to back for the rest of the operation. 202

5. Change the distilled water two more times, adding a volume of 300 to 500 ml each time, and letting the print (or prints) remain there for a total of 3 to 5 minutes. 6. Fix for 5 minutes in a tray containing 500 ml of a sodium thiosulfate solution (see Table 5.7). During the first moments of fixing, print tonality will alter considerably, moving from an intense, inky quality towards a warmer, softer effect, in combination with a very slight bleaching action. For the rest of the fixing bath, the print should not change much. Note: substituting a 5 percent sodium chloride solution for distilled water in the second water rinse in step 5 will affect a similar alteration in print tonality.18 Using a salt solution in the rinsing stage also serves to extend the life of the fixer, and to neutralize its toning and bleaching tendencies. Prints rinsed in sodium chloride take on a slightly redder hue than prints rinsed in distilled water alone. 7. Turn on the overhead lights and transfer the print to a second, identical fixing bath. Fix for an additional 15 minutes. For more on checking, replacing, and disposing used fixing baths, see Chapter 4. 8. After fixing, wash the print for 3 to 4 minutes in running water. Then transfer it to a tray containing 500 ml of a 1 percent sodium sulfite solution (see Chapter 4 and Table 4.12), which serves as a washing aid and helps to eliminate fixer from the fibers of the paper. Leave it in this bath for a total of 3 to 4 minutes. 9. Wash the print for 30 to 60 minutes in running water, depending on the thickness of the paper and the amount of sizing used (that is, 30 minutes for thin paper and 60 minutes for normal paper). Rotate the prints and change the water occasionally, taking care not to tear the paper. With thin paper, use the basket described in Chapter 4, if needed. 10. Dry face up on a screen. Thin marker papers should be dried between blotters in a contact printing frame, as was done with drying negatives. Upon drying, print tonality should cool somewhat, in combination with a slight, darkening, drying-down effect. 11. Clean up thoroughly once you are through. For more on cleaning trays and waste disposal after processing, see Chapter 4.

THE SERUM PROCESS This section is devoted to a process described by Thomas Sutton in 1855, and uses a dairy product known as whey, or milk-serum, instead of salt.19 Papers used in combination with whey are used without additional sizing and are immersed rather than floated. The 203

Table 5.7

Salt-Print Fixing Bath

Distilled water at 68°F (20°C) 1000 ml Sodium thiosulfate 120 grams Source: Adapted from E. de Valicourt, Nouveau manuel complet de photographie sur métal, sur papier, et sur verre (Paris: Librairie Enyclopédique de Roret, 1862), vol. 2, 210–211. This solution should be made slightly ahead of time since it cools slightly upon adding the sodium thiosulfate. Divide into two 500 ml baths before using. Depending on the strength of the sensitizing solution, the capacity is four to six 8-1/2≤ ¥ 11≤ prints. For the proper disposal of an exhausted fixer solution, see Chapter 4. Use a straight hypo solution since the addition of an alkaline like sodium carbonate will cause the print to bleach considerably.

reason for avoiding extra sizing is because of the lactic acid in the whey, which eats away the sizing and penetrates the fibers of the paper. The paper is immersed during sensitizing because the sensitizer will migrate to the backside anyway, due to this penetrating action. Papers ranging from 13 to 24 lb. work best with this process. A method for making whey is described below.

Whey-Making Procedure Listed below are the procedural steps involved in making sweet whey using rennet.20 As it takes about 8 to 16 hours for the rennet to set up, I like to start the initial steps in the evening and to finish the next morning. The entire procedure can be conducted in the kitchen. The by-product milk solid, while not needed for photographic purposes, is known as new cheese. Rather than throwing it away, you might consider using it in cooking. It has qualities similar to silken tofu and yogurt. If you do keep the cheese, make sure that you use an enamelware pot suitable for cooking and filtering muslin reserved for whey-making purposes only. Note that other whey-making procedures, such as curdling milk with citric or acetic acid, yielding sour whey, are not recommended here.21 Refer to the illustration (see Figure 5.5) in relation to the following procedural steps: 1. Preheat oven to 175°F (80°C). 2. Pour 1/2 gallon of fresh, skim milk (1 percent milk-fat) into an enamelware pot. Cover the pot with a lid and place it in the oven. Slowly bring the temperature of the milk up to 87 to 90°F (31 to 33°C), checking it occasionally with a glass thermometer. 3. While the milk is warming in the oven, measure out 1/4 cup of distilled water at room temperature. Remove the liquid rennet from the refrigerator and add 1/4 teaspoon of it to the 1/4 cup distilled water. Stir the solution for 1 minute so as to evenly distribute the rennet. Return the rest of the rennet to the refrigerator. Stored there, it should keep up to one year. Note that the measuring utensils should be plastic, not metal. 204

A

B

4. Once the milk has reached 87 to 90°F (31 to 33°C), remove it from the oven and add half a teaspoon of the distilled water-rennet mixture. Stir with a wooden spoon for about 3 minutes so as to evenly distribute it. 5. Store the milk in a relatively warm and secure area like the top of a refrigerator, and wait 8 to 16 hours while the rennet sets up. Cover the pot and do not stir it; let it rest peacefully. After about 3 to 6 hours, the milk should take on a quality similar to homemade yogurt. After about 8 hours, there should be a noticeable separation between a yogurt-like milk solid and a green-yellowish, clarified liquid, accompanied by a slightly sour odor. Waiting the full 16 hours makes this separation more pronounced. The liquid is the whey and the milk solid is new cheese. 6. Fold a 1-yard-square piece of muslin (fine cheesemaker’s cloth, not what is commonly referred to as cheesecloth) in half twice, making a four-layer thickness. Lay the folded muslin in a plastic colander and carefully decant the whey into another enamelware pot, using the muslin as a filter. Make sure that any stray milk solids fall into the muslin and not the pot. 7. Once the initially separated whey has been decanted, pour the large mass of remaining milk solids into the muslin, letting the whey continue to drain into the pot. Gather up the four corners of the muslin so as to form a sack, gripping its top and four corners with one hand to make sure that none of the milk solids spill out. Slowly squeeze and prod the sack until the rest of the whey has streamed into the pot, leaving only milk solids behind. This may take a few minutes. A half gallon of 1 percent milk-fat skim milk should yield 700 to 1000 ml of whey. 8. Remove milk solids from muslin and rinse it out thoroughly, hanging it up to dry afterwards. 9. Place the enamelware pot filled with whey on the stove and slowly bring it to a boil, stirring it occasionally with a wooden spoon. Boil for 1 to 2 minutes, stirring constantly. The whey should turn slightly more yellow, accompanied by a pleasant aroma similar to buttered popcorn.

C Figure 5.5A, B, and C Stages in preparing whey. (A) Fine muslin folded in a colander. (B) Pouring the whey and milk solids into the colander. (C) Gathering up the four corners of the muslin and straining the whey into an enamelware pot.

205

10. Remove the whey from the heat and decant it through a second, 1-yard square of muslin, placed in the colander, above a measuring cup. Once the whey has been poured off, let it cool to room temperature and it is ready for use. The useful working life of whey stored at room temperature is about 2 days. 11. Rinse the muslin out thoroughly and hang it up to dry. Both squares of muslin can be reused indefinitely. Once they are dry, fold them up neatly and store them in a plastic bag to keep dust away.

Whey: Immersion Procedure The steps involved in immersing paper using whey are identical to those described for iodizing the paper negative (see Chapter 4). Given a 500 ml volume of whey, you may immerse up to six sheets at a time, taking care to avoid trapping air-bubbles in between the sheets. Leave each sheet in the bath for about 5 minutes, then hang to dry as before. There is no noticeable color change of the paper in using whey. Kept in an archival box, in dry conditions, they should keep several months.

Sensitizing Procedure With the exception of the amount of time involved, sensitizing with the serum process is similar to sensitizing with the dry, waxed-paper negative process. As always, TAKE THE NECESSARY PRECAUTIONS IN WORKING WITH SENSITIZING SOLUTIONS. Under a safelight, immerse two sheets of paper back to back, in one of three variable contrast sensitizing baths (see Tables 5.8 to 5.10). Leave the paper in the sensitizing bath for 2 to 3 minutes, then hang them to dry by one corner in the dark. Place a small piece of paper in the lowest hanging corner to absorb the excess sensitizer that collects there. Once dried, they are ready for printing with a negative. Sensitized sheets are best used within 24 hours, although exposing up to 3 days later is also possible in dry conditions. Since the paper does not contain sodium or ammonium chloride, the silver bath only weakens slightly during sensitizing. Consequently, the sensitizing baths may be used again and again without needing to be replenished. With time and use, however, they will start to darken and need purifying. Purification is done in the same way as the other sensitizing solutions, by adding 5 grams of kaolin to each 330 ml bottle, then capping it and giving it a good shake to allow the kaolin to pull down any impurities as it settles (see Chapter 4).

Exposing Procedure The procedure for exposing prints using the serum process is identical to that of the other developing-out processes. Due to the 206

Table 5.8

Serum Process Sensitizer No. 1

Distilled water 300 ml Silver nitrate 15.4 grams Glacial acetic acid 15 ml Source: Adapted from Thomas Sutton, A New Method of Printing Positive Photographs, By Which Permanent and Artistic Results May Be Uniformly Obtained (St. Brelade’s Bay, Jersey: n.p., 1855) 11. Use this sensitizer in combination with normal-contrast negatives, for normalcontrast prints. It may either be strengthened or diluted to arrive at either serum process sensitizer no. 2 (see Table 5.9) or no. 3 (see Table 5.10).

Table 5.9

Serum Process Sensitizer No. 2

Distilled water 300 ml Silver nitrate 10.2 grams Glacial acetic acid 10 ml Source: Adapted from Thomas Sutton, A New Method of Printing Positive Photographs, By Which Permanent and Artistic Results May Be Uniformly Obtained (St. Brelade’s Bay, Jersey: n.p., 1855) 11. Use this solution in combination with thin, or low-contrast, negatives for higher contrast prints. It renders delicacy of detail rather than deep blacks. The solution may also be made by diluting serum process sensitizer no. 1 (see Table 5.8).

Table 5.10 Serum Process Sensitizer No. 3 Distilled water 300 ml Silver nitrate 20.5 grams Glacial acetic acid 20 ml Source: Adapted from Thomas Sutton, A New Method of Printing Positive Photographs, By Which Permanent and Artistic Results May Be Uniformly Obtained (St. Brelade’s Bay, Jersey: n.p., 1855) 11. Use this solution in combination with harsh, or contrasting, negatives to arrive at lower-contrast prints. It renders increased mid-tones with deep blacks. The solution may also be made by strengthening either serum process sensitizer no.1 (see Table 5.8) or no. 2 (see Table 5.9).

absence of silver chloride, the sensitized paper is not quite as lightsensitive as the developing-out salt processes. Exposure times vary from 4 to 20 minutes, depending on the weather conditions and lightlevel involved. Expose until most of the image is visible, except the highlights.

Developing Procedure Development differs from developing-out salt prints in that the prints are immersed in a tray, either individually or back to back, rather than floated. Use about 100 ml of a 0.8 percent solution of gallic acid per print, and develop for about 5 minutes at room tem207

perature. Once again, development is checked by inspection, under a safelight, briefly illuminating a dim, incandescent bulb or yellow bug-light from a distance. Carry the development until the print is slightly darker than you want the final image to be since it will bleach slightly in the subsequent stages. Normally, the print will be a strong shade of purple, similar to squid ink, upon leaving the developer. Rinsing after development differs slightly from developed-out salt prints, and is achieved in the following manner: 1. Prints are placed in a bath containing 300 to 500 ml of distilled water for 3 to 5 minutes. 2. The water is drained and replaced by 300 to 500 ml of distilled water, to which 1/8 to 1/4 teaspoon of sodium chloride has been added. The print is placed in this second bath for 3 to 5 minutes. Here it bleaches slightly and alters tonality, shifting towards a golden or reddish brown. 3. This is followed by a third bath of 300 to 500 ml distilled water for 3 to 5 minutes.

Toning Procedure Untoned prints using the serum process take on an attractive, golden or reddish-brown hue upon drying. Still, you may want to tone the print before fixing to take this tonality from warm brown to cool sepia, or even blue (Color Plate X). Just about any gold toner used for printing-out paper will work. The sodium acetate-gold chloride toner given below (see Table 5.11) is especially recommended for the

Table 5.11 Sodium Acetate Gold-Toner Distilled water at 68°F (20°C) 75 ml Sodium acetate (fused) 2 grams Gold chloride (1% solution) 4 to 5 ml Distilled water at 68°F (20°C) to make a total volume of 100 ml Source: Adapted from James Reilly, The Albumen and Salted Paper Book (Rochester, N.Y.: Light Impressions, 1980), 80. Pour 75 ml of distilled water into a beaker (or measuring cup). Add the sodium acetate and stir until it is completely dissolved. Then add the gold chloride solution and stir until it is completely blended. Add distilled water to make a total volume of 100 ml and stir until it is completely blended. ALWAYS TAKE THE NECESSARY PRECAUTIONS IN WORKING WITH GOLD CHLORIDE: WEAR AN APRON, SAFETY GLASSES, AND NITRILE GLOVES WHEN MIXING UP THE SOLUTION. WEAR EXAMINATION GLOVES WHEN HANDLING THE PAPER IN SOLUTION. The toner should be allowed to settle for 1 hour before using. Between the exposure of the print and processing, it is also a good idea to trim off excess marginal areas of the print that would needlessly exhaust the gold in the toning solution. With a fresh toning bath, place one or two of the trimmed margins into the bath prior to toning to avoid an unequal toning of the first print. Capacity is about four to six 8-1/2≤ ¥ 11≤ prints.

208

wide range of tones that can be obtained. Having mixed up the toning bath, proceed in the following way: 1. Pour 100 ml of the toning solution into a glass or enamelware tray. 2. Lift the first print out of the distilled water rinse, allow it to drain briefly, and immerse it face down into the gold toning solution. If you process another print at the same time, let the second print remain in the distilled water bath until the first print has been completely immersed in the toning solution. Then add the second to the toning bath in the same way, face up, with the prints back to back. 3. Toning takes from 3 to 20 minutes, depending on the strength of the bath and the tone desired. For warmer tones, leave the print in the solution for less time; for cooler tones, longer. Gently agitate the solution by tipping the corner of the tray occasionally. Tone until the print is slightly warmer than you want it to be since it cools slightly upon drying. 4. When the desired tone is reached, transfer the print to a distilled water bath for 1 to 3 minutes in order to rinse it before moving on to the fixing stage. This prevents weakening the fixer.

Fixing and Washing the Print After rinsing and the optional toning step, prints are then fixed in two identical 10 percent sodium thiosulfate baths for 10 minutes each. After fixing, they are rinsed in tap water, placed in a 1 percent sodium sulfite washing aid (see Chapter 4, Table 4.12), washed, and dried in exactly the same manner as with developed-out salt prints. Clean up thoroughly once you are through. For more on cleaning trays and waste disposal after processing, see Chapter 4.

NOTES 1. In recent years, a number of books have appeared with sections on printed-out salt printing. The most important of these remain James Reilly, The Albumen and Salted Paper Book (Rochester, N.Y.: Light Impressions, 1980); and William Crawford, The Keepers of Light (Dobbs Ferry, N.Y.: Morgan and Morgan, 1979). 2. I am indebted to Joel Snyder of the University of Chicago for assisting me in forming this list of the relative merits of developing-out as opposed to printing-out. 3. Lyndon Smith, Photographic Notes, vol. 6, no. 121 (April 15, 1861): 120. 4. For more on Blanquart-Évrard’s industry-based approach, see Helmut Gernsheim (in collaboration with Alison Gernsheim), The History of Photography, rev. ed. (London: Thames and Hudson, 1969), 188– 189. 5. Gernsheim, History of Photography, 189.

209

6. This summary of the working relations between Blanquart-Évrard and Sutton has been adapted from Gernsheim, History of Photography, 335–337; and Crawford, The Keepers of Light, 48–49. For more on Sutton’s relation to Blanquart-Évrard, see Helmut Gernsheim, “Cuthbert Bede, Robert Hunt, and Thomas Sutton,” in One Hundred Years of Photographic History: Essays in Honor of Beaumont Newhall, ed. Van Deren Coke (Albuquerque: University of New Mexico Press, 1975), 64–67. 7. For a good example of the prevalence of Gersheim’s view that developing-out prints are to be exclusively associated with neutral tones, see James Reilly, Care and Identification of 19th-Century Photographic Prints (Rochester, N.Y.: Photographic Products Group, Eastman Kodak, 1986), 5–6. 8. Thomas Sutton, A New Method of Printing Positive Photographs, By Which Permanent and Artistic Results May Be Uniformly Obtained (St. Brelade’s Bay, Jersey: n.p., 1855) 20. 9. Thomas Sutton, “On Printing by Development,” Photographic Notes, 2nd ed., vol. 1, no. 1 ( January 1, 1856): vii–viii. 10. Sutton, New Method, 1855, 7. 11. This alternative to a contact-printing frame is taken from Charles Fabre, Traité encyclopédique de photographie (Paris: Gauthier-Villars, 1890), vol. 3, 43–45. 12. For Hardwich’s developing-out procedures, see T. Frederick Hardwich, A Manual of Photographic Chemistry, 4th ed. (London: John Churchill, 1857). I would like to thank Joel Snyder of the University of Chicago for bringing this book to my attention. 13. The composition of sea salt is given in Thomas Sutton, A Dictionary of Photography (London: Sampson Low, 1858), 365. 14. Sutton, A Dictionary of Photography, 339. 15. Slow removal of the paper from the sensitizing solution, in order to prevent drips, was suggested in Reilly, Albumen and Salted Paper, 61. 16. For more on using an artificial exposing unit in combination with a test-strip approach to developing-out platinum printing, see Richard Sullivan and Carl Weese, The New Platinum Print (n.p.: Working Pictures, 1998) 53–55. For more on how to build an artificial exposing unit, see Laura Blacklow, New Dimensions in Photo Processes, 3rd rev. ed. (Boston: Focal Press, 2000), 45–53; and Sullivan and Weese, The New Platinum Print, 86–88. 17. Using a bug-light is recommended in Reilly, Albumen and Salted Paper, 7. 18. Rinsing the print in sodium chloride is suggested in E. de Valicourt, Nouveau manuel complet de photographie sur métal, sur papier et sur verre (Paris: Librarie Encyclopédique de Roret, 1862), vol. 2, 203–204. 19. Using whey as a substitute for salt is discussed in Sutton, New Method, 9–10. 20. The procedure for making whey has been adapted from Sutton, New Method, 9–10. 21. On the distinction between sweet whey and sour whey, see Sutton, A Dictionary of Photography, 357.

210

Color Plate I Maxime Du Camp, The Colossus of Abu Simbel, c. 1850- 51. This photograph, printed by BlanquartEvrard, is an example of the neutral tone typically associated with developing-out processes. Reprinted from Maxime Du Camp, Egypte, Nubie, Palestine et !?Jrie (Paris, 1852), plate I 06. Reproduced by permission of the Department of Printing and Graphic Arts, Houghton Library, Harvard College Library.

Color Plate II David Octavius Hill and Robert Adamson, Patrick Byrne, the Blind Irish Harper, 1845. This photograph is an example of the warm tone typically associated with printing-out salt processes. Reproduced courtesy of the Fogg Art Museum, Harvard University Art Museums, Gift of David Becker, Mrs. Phyllis Lambert, and Mr. and Mrs. Herbert W. Pratt.

Color Plate III Thomas Sutton, Jersey, 1856. Given the date of the photograph, it is quite possible that Sutton made this print using developing-out processes he described in 1855. Note the warm, chocolatebrown tone, rather than the neutral tone that is typically associated with developing-out processes. Reproduced courtesy George Eastman House.

Color Plate IV This print was made following Sutton's developing-out procedures (Salting Solution No. I in combination with Print Sensitizing Solution No. 1), using Southworth Resume paper given a preliminary, flotation sizing upon 1 percent potato starch. A warm, chocolate-brown tone was the result.

Color Plate V The effect of changing exposure and development times. (A) This print was made using Salting Solution No. I and Print Sensitizing Solution No. l. It was exposed for 20 minutes to cloudy skies, then developed for about 6 minutes upon a saturated, gallic acid developer. The result was a reddish, russet brown tonality. (B) This print was made using the same salting and sensitizing solutions, but the exposure was 4 minutes and the development 20 minutes. The result was a darker brown, sepia tonality.

A

B

Color Plate VI The effect of changing exposure and development times. (A) This print was made using Salting Solution No. 3 and Print Sensitizing Solution No. 3. It was exposed for I 0 minutes to cloudy skies and then developed for 3 minutes upon a saturated, gallic acid developer. The result was a split tonality, with warm shadows and neutral highlights. (B) This print was made using the same salting and sensitizing solutions, but exposed for 4 minutes and developed for 7 minutes. The result was a neutral tonality.

A

B

Color Plate VII The effect of using diiTerent kinds of salt. (A) This print was made using Salting Solution No. I and Print Sensitizing Solution No. I, with the salting solution consisting of pure sodium chloride. The result was a reddish, russet brown tonality. (B) This print was made using the same salting and sensitizing solutions, with the exception being that French sea salt was substituted for sodium chloride. The result was a sepia tonality.

A

B

Color Plate VIII Using a weakened sensitizing solution to print a high-contrast negative. (A) This print was made with a freshly made sensitizer, the result being high in contrast. (B) This print was made with the same sensitizer, but after it already had been used to sensitize seven sheets. The result is a print in which contrast is significantly reduced.

A

B

Color Plate IX Staining resulting from the failure to absorb excess solution from the lowest hanging corner of the print as it dries after sensitizing. (A) In sensitizing this sheet of paper, a small piece of paper was never attached to the lowest hanging corner as it hung to dry. The result was a slightly blue, diagonal stain in the upper right-hand corner of the print. (B) A print from the same negative in which a small piece of paper had been applied does not exhibit this staining tendency.

A

B

Color Plate X

Toning a serumprocess print. (A) An untoned print, using Serum-Process Sensitizer No. I and developed in a saturated solution of gallic acid. Print tonality has a golden brown hue. (B) A print made the same way, except that it was placed in a weakened, sodium acetate gold-toning solution for about 20 minutes after development. The result is a redder tonality, coupled with a slight intensification of the shadow areas.

A

B

•

Sources of Supplies Listed below are the addresses, telephone numbers, and websites of some of the companies who manufacture or retail the materials, chemicals, and equipment considered in this book. These may be particularly useful to people living in isolated or rural areas. They are also a great source of product information. Note that a few of these companies deal with wholesale purchases only, rather than individual retail sales; nevertheless, they will probably be quite willing to refer you to a retail seller in your area should you need to locate one.

WOOD • Aircraft Spruce & Specialty Company, P.O. Box 4000, 225 Airport Circle, Corona, CA, 91720; (800) 861-3192; www.aircraftspruce.com. (This company cuts spruce to specified dimensions, at a reasonable rate. Spruce can be used as a substitute for basswood.) • Midwest Products Company, 400 South Indiana Street, Hobart, IN 46342; (800) 348-3497; www.midwestproducts.com. (Supplier of basswood to many art-supply and hardware stores.)

SHEET METAL • K & S Engineering, 406 70th Street, Darien, IL 60561; (877) 266-3559; www.modeltool.com. (Supplier of sheetmetal to many art-supply and hardware stores.)

OPTICAL COMPONENTS • American Science & Surplus, Inc., 3605 Howard Street, Skokie, IL 60076; (847) 982-0870; www.sciplus.com. (Often 211

has optical surplus and cheap copy lenses for sale.) • Anchor Optical Surplus, 4124 Edscorp Building, Barrington, NJ 08007-1380; (856) 573-6865; www.anchoroptical.com. (An inexpensive source for surplus lens elements.) • Edmund Industrial Optics, 101 East Gloucester Pike, Barrington, NJ 08007-1380; (856) 573-6250; www.edmundoptics.com. • Surplus Shed, 407 U.S. Route 222, Blandon, PA 19510; (877) 778-7758; www.surplusshed.com. (Often has optical surplus and cheap copy lenses for sale.)

CHEMICALS • Artcraft Chemicals, P.O. Box 583, Schenectady, NY 12301; (800) 682-1730; www.artcraftchemicals.com. (All-around source for photographic chemicals and alternative process supplies.) • Baddley Chemicals, 11230 Cloverland Avenue, Baton Rouge, LA 70898; (800) 356-6696; www.baddley.com. (Inexpensive source for silver nitrate and bromides.) • D.F. Goldsmith, 909 Pitner Avenue, Evanston, IL 60202; (847) 869-7800; www.dfgoldsmith.com. (Inexpensive source for silver nitrate and gold chloride.) • H & S Chemical Company, 1025 Mary Laidley Drive, Covington, KY 41017; (859) 356-8000; www.hschem.com. (Inexpensive source for iodides.) • Photographers’ Formulary, P.O. Box 950, Condon, MT 59826; (800) 922-5255; www.photoformulary.com. (Allaround source for photographic chemicals and alternative process supplies.)

LAB AND SAFETY EQUIPMENT • American Science & Surplus, 3605 Howard Street, Skokie, IL 60076; (847) 982-0870; www.sciplus.com. (Often has inexpensive glass bottles, graduates, and triple-beam balances for sale.) • Lab Safety Supply, 401 South Wright Street, Janesville, WI 53546; (800) 356-0783; www.labsafety.com. (All-around supplier of labware, glassware, organic vapor masks, aprons, gloves, etc.) • Scientifics, 101 East Gloucester Pike, Barrington, NJ 080071380; (800) 728-6999; www.scientificsonline.com. (Source of general-purpose labware and triple-beam balances.)

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PAPER • Borden & Riley, 184-10 Jamaica Avenue, Hollis, NY 11423; (800) 221-1416; www.artproducts.com. • Clearprint Paper Company, Emeryville, Ca; (800) 7667337; www.clearprintpaper.com. • Crane & Company, 30 South Street, Dalton, MA 01226; (413) 684-2600; www.crane.com. • Hunt Corporation, Statesville, NC 28677; (800) 879-4868; www.hunt-corp.com. (Makers of Bienfang papers.) • Lindenmeyr-Munroe, 3 Manhattanville Road, Purchase, NY 10577-2110; (914) 696-9000; www.lindenmeyr.com. (Distributes office stationery in large, flat-sheet sizes.) • National Printfast, 5717 West 80th Street, Indianapolis, IN 46278; (800) 388-9516; www.printfast.com. • Southworth Company, 265 Main Street, Agawam, MA 01001; (800) 225-1839; www.southworth.com.

BEESWAX • Artcraft Chemicals, P.O. Box 583, Schenectady, NY 12301; (800) 682-1730; www.artcraftchemicals.com. • Sioux Honey Association, P.O. Box 502579, St. Louis, MO 63150-2579; (712) 258-0638; www.suebee.com.

LARGE-FORMAT FILMS • Freestyle Camera, 5124 Sunset Boulevard, Los Angeles, CA 90027; (800) 292-6137; www.freestylesalesco.com. (Has inexpensive, panchromatic sheet film and ortho-litho film in 8 ¥ 10 and 10 ¥ 12 format sizes.) • Photo Warehouse, 120 Bernoulli Circle, Oxnard, CA 93030; (800) 922-5484. (Has inexpensive, panchromatic sheet film and ortho-litho film in 8 ¥ 10 and 10 ¥ 12 format sizes. An excellent all-around source for inexpensive, off-brand blackand-white supplies.)

ARCHIVAL STORAGE • Gaylord Brothers, P.O. Box 4901, Syracuse, NY 132214901; (800) 448-6160; www.gaylord.com. (Archival envelopes and boxes for negative and print storage.) • Light Impressions, P.O. Box 22708, Rochester, NY 146922708; (800) 828-6216; www.lightimpressionsdirect.com.

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MILK-SERUM COMPONENTS • New England Cheesemaking Supply Company, P.O. Box 85, Ashfield, MA 01130; (413) 628-3808; www.cheesemaking.com. (Source for the liquid rennet used in making milk-serum; also has fine muslin.)

CONTACT PRINTING FRAMES • Great Basin Photographic, HCR 33 Box 2, Las Vegas, NV 89124; (702) 363-1900; www.greatbasinphoto.com. (Specializes in contact printing frames.) • Photographers’ Formulary, P.O. Box 950, Condon, MT 59826; (800) 922-5255; www.photoformulary.com. (An all-around source for alternative process supplies.)

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Ed. Van Deren Coke. Albuquerque: University of New Mexico Press, 1975. Gernsheim, Helmut, and Allison Gernsheim. L. J. M. Daguerre: The History of the Diorama and the Daguerreotype. 2nd revised edition. New York: Dover, 1968. ——. The History of Photography. Rev. ed. London: Thames and Hudson, 1969. Greenleaf, Allen R. Photographic Optics. New York: Macmillan, 1950. Guillot-Saguez, [A.]. Méthode théorique et pratique de photographie sur papier. Paris: Victor Masson, 1847. Hammond, John H. The Camera Obscura: A Chronicle. Bristol [U.K.]: Adam Hilger, 1981. Hardwich, T. Frederick. A Manual of Photographic Chemistry. 4th ed. London: John Churchill, 1857. Hodgman, Charles D. ed. Handbook of Chemistry and Physics. 36th ed. Cleveland: Chemical Rubber Publishing, 1954. Horne and [W.H.] Thornthwaite. Horne & Thornthwaite’s Descriptive Catalogue of Scientific Instruments. 4th ed. London: [self-published], 1855. Hunt, Robert. A Manual of Photography. 1853. Reprint, New York: Arno, 1973. Jammes, André, and Eugenia Parry Janis. The Art of French Calotype. Princeton [NJ]: Princeton University Press, 1983. Janis, Eugenia Parry. The Photography of Gustave Le Gray. Chicago: Art Institute of Chicago, 1987. Janis, Eugenia Parry, and Josiane Sartre. Henri Le Secq, photographe de 1850 à 1860. Paris: Musée des Arts Décoratifs, 1986. Jay, Paul, and Michel Frizot, comps. Nicéphore Niépce. 2nd ed. Photo Poche 8. Paris: Centre National de la Photographie, 1983. Keith, Thomas. “Dr. Keith’s Paper on the Waxed Paper Process.” Photographic Notes, vol. 1, no. 8 (July 17, 1856): 104. This article is reprinted in its entirety, along with later corrections, in Hans Kraus, Jr. [Firm], Sun Pictures. Catalogue Six. Dr. Thomas Keith and John Forbes White (New York: Hans Kraus, Jr., [1993?]), 61–63. Kingslake, Rudolf. Lenses in Photography: The Practical Guide to Optics for Photographers. Garden City [NY]: Garden City, 1951. ——. Lens Design Fundamentals. New York: Academic Press, 1978. ——. A History of the Photographic Lens. Boston: Academic Press, 1989. Le Gray, Gustave. Traité pratique de photographie sur papier et sur verre. Paris: Germer Baillière, 1850. ——. Nouveau traité théorique et pratique de photographie sur papier et sur verre. Paris: Lerebours et Secretan, 1851. Lerebours, N[öel]-P[aymal]. Traité de photographie. 4th ed. Paris: Lerebours, 1843. Litchfield, R.B. Tom Wedgwood: The First Photographer. London: Duckworth, 1903. Lockett, Arthur. Camera Lenses: A Useful Handbook for Amateur and Professionel Photographers 2nd ed. Revised by H.W. Lee. New York: Pitman, 1947. Lothrop, Eaton S., Jr. A Century of Cameras. Dobbs Ferry, N.Y.: Morgan & Morgan, 1973. McDaniel, Malcolm. The Photography of Édouard Baldus. New York: The Metropolitan Museum of Art, 1994. Monckhoven, D[ésiré] v[an]. Méthodes simplifiées de photographie sur papier. Paris: Marion, 1857. ——. Traité général de photographie. 3rd ed. Paris: Victor Masson, 1863.

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——. Traité d’optique photographique. Paris: Victor Masson, 1866. Morris, Richard. Calotype Negatives. In Coming into Focus: A Step-By-Step Guide to Alternative Photographic Printing Processes, edited by John Barnier. San Francisco: Chronicle Books, 2000. Parr, W.D. “On the Use of Acetate of Soda as an Accelerator.” Journal of the Photographic Society, no. 43 (June 21, 1856), 65–66. Pélegry, Arsène. La Photographie: des peintres, des voyageurs et des touristes. Paris: Gauthier-Villars, 1885. “Pocket camera obscura.” The Magazine of Science, vol. 4, no. 7 (May 14, 1842): 49–50. Reilly, James. The Albumen and Salted Paper Book. Rochester, N.Y.: Light Impressions, 1980. ——. Care and Identification of 19th-Century Photographic Prints. Rochester, N.Y.: Photographic Products Group, Eastman Kodak, 1986. Rempel, Siegfried, and Wolfgang Rempel. Health Hazards for Photographers. New York: Lyons and Burford, 1992. Renner, Eric. Pinhole Photography: Rediscovering a Historic Technique. 2nd ed. Boston: Focal Press, 1999. Schaaf, Larry. Out of the Shadows: Herschel, Talbot and the Invention of Photography. New Haven [CT]: Yale University Press, 1992. ——. The Photographic Art of William Henry Fox Talbot. Princeton [NJ]: Princeton University Press, 2000. Shaw, Susan, and Monona Rossol. Overexposure: Health Hazards in Photography. 2nd ed. New York: Allworth Press, 1991. Smith, Lyndon. Photographic Notes, vol. 6, no. 121 (April 15, 1861): 120. Snelling, H[enry] H[unt]. A Dictionary of the Photographic Art. 1854. Reprint. New York: Arno, 1979. Sparling, W. [Marcus]. Theory and Practice of the Photographic Art. 1856. Reprint. New York: Arno, 1973. Stevenson, Sara, Julie Lawson, and Michael Gray. The Photography of John Muir Wood 1805–1892, An Accomplished Amateur. N.p.: Scottish National Portrait Gallery, 1988. Sullivan, Richard, and Carl Weese. The New Platinum Print. N.p.: Working Pictures, 1998. Sutton, Thomas. A New Method of Printing Positive Photographs, By Which Permanent and Artistic Results May Be Uniformly Obtained. St. Brelade’s Bay, Jersey: n.p., 1855. ——. The Calotype Process: A Hand Book to Photography on Paper. London: Joseph Cundall, 1855. ——. “On Printing by Development.” Photographic Notes, 2nd ed., vol. 1, no. 1 (January 1, 1856): vii–viii. ——. A Dictionary of Photography. London: Sampson Low, 1858. ——. “A New View-Lens.” Journal of the Photographic Society, no. 78 (February 5, 1859): 169–173. ——. “Description of a New Photographic Lens, Which Gives Images Entirely Free from Distortion.” Journal of the Photographic Society, no. 90 (October 15, 1859): 58–59. Turner, Silvie. Which Paper?: A Review of Fine Papers for Artists, Craftspeople and Designers. London: Estamp, 1991. Valicourt, E. de. Nouveau manuel complet de photographie sur métal, sur papier, et sur verre. 2 vols. Paris: Librairie Enyclopédique de Roret, 1862.

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Index Subjects considered in this book are listed below, along with corresponding page numbers. In cases where numerous page numbers are to be found for a particular subject, highlighted page numbers will refer the reader to where that subject is most fully discussed. Aberrations, 81, 85, 89, 92–99 astigmatism, 92, 98–99, 113, 116, 137 chromatic aberration, 62, 92, 94–95, 101, 102, 112, 116, 134, 137 coma, 92, 94, 108, 136 curvature of field, 89, 92, 95–97, 98, 103, 108, 111, 113, 117, 120, 125, 137 curvilinear distortion, 92, 97–98, 101, 103, 108, 116–17, 125, 137 barrel distortion, 97–99, 127 pincushion distortion, 97–98 spherical aberration, 92–94, 96, 136 Absolute focal length. See Focal length Acceleration. See Development Acetic Acid. See Glacial acetic acid Achromatic lenses. See Lenses Adamson, Robert. See Hill and Adamson Alcohol. See Ethyl alcohol Alkalinity, 142, 151, 167, 187, 204 Ammonium acetate, 165–66, 179 Ammonium bromide, 140, 147 Ammonium chloride, 184, 185, 196–97, 206 Ammonium iodide, 139, 140, 147, 166 Angle of view, 3, 10, 81, 88–89, 90, 99, 101, 103, 108–09, 111–12,

113, 128, 136, 137. See also Field of view narrow-angle, 10, 88–89, 90, 94, 99, 101, 103, 104, 108, 111, 117, 126, 127, 136 normal-angle, 10, 88–89, 90, 112, 136 wide-angle, 10, 88–89, 90, 112, 136 wide-field, 10, 88–89, 90, 112, 128, 136 Aperture, 85, 90–91, 94, 97, 101, 104, 108, 110, 111, 113, 116–18, 121, 125–27 actual aperture, 91, 136 effective aperture, 91, 113, 136 Steinheil’s method for determining, 91 stops, 81, 86, 90–91, 94, 96–101, 103–18, 120–22, 124–29, 131 changing f-stops, 60, 108–09, 115–16, 125, 131 construction of stops, 107, 114, 124, 129 determining f-stop number, 91 location of stops, 90–91, 97–98, 100–01, 103, 108–11, 113, 116–18, 120–22, 125–28, 131 Architectural drafting vellum, 142–43. See also Paper

Archival storage, 148, 170, 173, 195, 206 sources of supply, 213 Arno reprint editions, ix, 35, 78–79, 179 Astigmatism. See Aberrations Baldus, Édouard-Denis, 145, 179, 216 Barrel distortion. See Aberrations Basswood frame-stock, 11–20, 24–32, 40–55, 58–60, 65–72, 76–78 sources of supply, 211 Bayard, Hippolyte, 3 Beeswax, 140, 167. See also Waxing procedure sources of supply, 213 Bi-concave lens. See Lens shapes Bi-convex lens. See Lens shapes Blanquart-Évrard, Louis-Désiré, ix, 4, 11, 35, 145, 182–84, 209–10, 215, Color Plate I Blotting paper, 141, 164, 167–70, 171, 173, 176, 203 Bolas, Thomas, 89–90, 94, 110, 116, 120–21, 136–38, 215 Book-cloth, 40, 66, 71–72, 75. See also Hinges, Ribbon Brass shim-stock, 100, 133–34. See also Sheet metal Brewster, Sir David, 34, 36, 215 Bromide, 139, 150, 156, 179. See also Ammonium bromide, Potassium bromide

219

Bug-light, 202, 208, 210. See also Safelight Buron, 104, 137 Calotypes, x, xiii, 1–8, 35, 81, 102, 119–20, 135, 139–80, 181–83, 215–17. See also Paper negatives Calcium carbonate, 140, 166–67, 185 Cameras, ix–xi, 1–5, 7, 9, 12–13, 16, 20, 22–24, 28, 32, 37–79, 81, 86–87, 91, 95, 121, 131–34, 139, 153, 215–17 folding-camera, 24, 28, 32, 63–76, 131–34 construction of, 65–75 use of, 75–76 materials needed for construction, 40–58, 65–78 sliding box-camera, 12, 16, 20, 37, 39, 41–63, 76, 78, 131–33 construction of, 42–57 platform base, 41, 47, 54–62 use of, 58–63 tools needed for construction, 40–58, 65–78 view-cameras, x–xi, xiv, 12–13, 20, 22, 62, 81 Cameron, Julia-Margaret, 93 Canaletto the elder (Giovanni Antonio Canal), 38 Cardano, Girolamo, 37 Card-stock, 11, 91, 135–36 Caulk. See Vinyl adhesive caulk C-clamps, 10, 13–14, 19–20, 26, 30–32, 50–52, 60–63 used in gluing wood, 13–14, 19–20, 26, 30–32, 50–52 used in making exposures, 60–63 Channing, William Francis, 3 Cheesecloth. See Muslin Chemicals, 139, 140–41, 144–57, 159–67, 171–79, 181–83, 184–85, 194–200, 202–04, 206–08 Sources of supply, 212 Chevalier, Charles, xi, 5, 35, 39, 79, 101, 118–21, 137–38, 147, 160, 178, 215 Chromatic aberration. See Aberrations Circle of definition, 22, 89, 101, 111–12, 117, 126–28, 136 Circle of illumination, 89–90, 136 Citric acid, 185, 199–200. See also Lemon juice

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Claudet, Antoine, 6, 35 Clean-up procedure (after processing), 166–67, 176 Clothespins, 141, 147, 173, 191, 193–94, 196 Clover, Professor, 38 Coffee filters, 141, 146, 152, 194 Collodion process. See Wet-collodion process Coma. See Aberrations Combined lens. See Lenses Compound lens. See Lenses Construction paper, 90, 100, 104, 107, 108, 114–16, 124, 128–31 Contact cement, 100, 123, 133. See also Glue, Vinyl caulk adhesive Contact printing frames, 141, 164, 176, 184, 186–87, 201–03 sources of supply, 214 Cooke triplet, 126–27, 138 Cuvelier, A[dalbert?], 147, 160, 178 Crundell, G.S., 108 Curvature of field. See Aberrations Curvilinear distortion. See Aberrations

Diameter. See Lenses Digital imaging, ix Distance between separated lens elements. See Lenses Distilled water, 140, 145–47, 149, 152, 155, 157, 159–60, 162, 164–65, 175–76, 185, 190, 195–96, 200, 202–05, 207–09 Double-glass design, for film-holders, 1, 11. See also Evaporation of negative Dowels, 11, 13, 15, 17, 25, 27 cutting, 13, 25 hammering, 15, 27 Dry, waxed-paper film-holder. See Film-holders Dry, waxed-paper process. See Paper negatives Drying paper, 144, 147–48, 164, 173, 176–77, 191–94, 196, 198, 203, 206, 208–09, Color Plate IX Du Camp, Maxime, 183–84, Color Plate I

Daguerre, Louis Jaques Mandé, 101, 137, 215 Daguerreotypes, xi, 3–9, 35, 39, 78, 118–19, 137, 215–16 Dallmeyer, John, 126, 138 Dark-cloth, 23, 40, 60 Darkroom, 142, 145, 150, 159, 165, 172, 174, 177, 197, 201 Dark-slides. See Film-holders Davanne, Alphonse, 36, 148, 167, 170, 172, 175, 179–80, 215 Davidson, Thomas, 108 Davy, Sir Humphry, 38, 79 Della Porta, Giovanni Battista. See Porta, Giovanni Battista della Developing. See Development Developing-out, xii, 181–210, Color Plate I, Color Plates III–IV salt-printing processes, xii, 181–84, 189–203, 209–10 serum process, 184, 188, 203–09 Development, 139, 141–42, 145, 149, 151, 159–66, 176–78, 179, 181–84, 189, 202–03, 207–08, 209–10, Color Plates V–VI. See also Gallic Acid acceleration, 165–66, 179 restraining, 165, 179 Diagonal. See Negative formats

Effective aperture. See aperture Equations, 84–86 two lenses in contact, 84–85 more than two lenses in contact, 85 two separated lenses, 85–86 Ethyl alcohol, 140, 160, 166, 176 Evaporation of negative, 1, 158–59 Exposing procedure, 60–62, 75–76, 158–59, 176, 201, 206–07 dry, waxed-paper negatives, 176 salt-printing, 201, Color Plates V–VI serum process, 206–07 wet-process negatives, 158–59 Fabre, Charles, 102, 111, 118–19, 137–38, 186–87, 210, 215 Field of view, 89, 112, 136. See also Angle of view Film-holders, x–xi, 1–36, 40–41, 47–48, 58, 60–64, 66, 69, 72, 75, 81, 92, 141, 144, 153, 155, 158, 161, 176 dry, waxed-paper film-holder, 1, 24–34, 63–64, 66, 69, 72, 75, 176 construction of dark-slides, 29–31

construction of end-cap, 29, 176 construction of main-frame, 24–28, 31–32 installing divider, 29, 176 use of, 33–34, 176 wet-process film-holder, 1, 11–24, 33–34, 41, 47–48, 58, 60–62, 92, 144, 153, 155, 158, 176 construction of dark-slides, 18–20 construction of end-cap, 18 construction of main-frame, 12–18, 20 use of, 151–56, 158, 161 Film plane, 37, 41, 62, 86, 89, 91, 94, 110, 134 Fixer remover, 163–64. See also Washing aid Fixer-testing solution (Kodak FT-1), 163 Fixing, 139, 143, 159–64, 177, 184, 203–04, 208, 209. See also Development Flachéron, Frédéric, 11, 98, 120 Flotation, 142, 153–54, 166, 189–92, 194, 196–99, 202–03, 207. See also Immersion Foam-core, 100, 105–08, 114–15, 124–25, 129–30, 135–36 Focal length, 2–3, 7–8, 10, 12, 39, 41, 58, 63–64, 81–86, 86–88, 88–89, 91, 95, 101–05, 111–14, 119–23, 125, 127–29, 131–32, 136 absolute focal length, 86–88 negative focal length, 82–85 positive focal length, 82–85 Focusing adjustment. See Aberrations Focusing loupe, 23, 40, 60, 164. See also Focusing procedure Focusing procedure, 23–24, 33–34, 37, 39, 59–60, 63, 75–76 Focusing screen, 1, 21–24, 33, 37, 41, 58–63, 75–76, 86–87, 91, 94–95, 118 dry, waxed-paper film-holder, 33–34, 63, 75–76 construction of, 33 use of, 33–34, 63, 75–76 wet-process film-holder, 21–24, 37, 58–62 construction of, 21–23 use of, 23–24, 58–62

Folding-cameras, historical designs, 38–39, 63–64, 78–79. See also Cameras Format. See Negative format f-stop. See Aperture Gallic acid, 139–40, 145, 159–61, 164–66, 176–79, 184–85, 202, 207. See also Development Gelatin. See Sizing Gernsheim, Helmut, 137, 182–84, 209–10, 215–16 Glacial acetic acid, 139–40, 150, 152, 156–57, 159, 161, 174–75, 177, 184–85, 200, 204, 207 Glass, 1–2, 11–12, 16, 18, 20, 21–24, 33–34, 91–92, 141, 144, 151, 153–55, 158, 161, 166–67, 186, 188, 198–200 used in focusing screen, 21–24, 33–34, 91 used in negative carrier, 1–2, 11–12, 16, 18, 20–21, 92, 141, 144, 151, 153–55, 158, 161 used in processing, 151, 153–55, 161, 166–67, 186, 188, 198–200 Glassine, 11, 21–24, 33–34 Glucose. See Sugar Glue, 11, 13–15, 19–20, 25–27, 30–32, 43, 45–48, 50–52, 55, 57, 66, 69, 71–72, 75–78, 135–36. See also Contact cement, Vinyl caulk adhesive Gold chloride, 182, 185, 208–09, 212 Grain alcohol. See Ethyl alcohol Grand Photographe, 39, 79 Graphic designers’ marker paper, 142–43, 188, 203. See also Paper Ground-glass. See Focusing screen Grubb’s method for determining absolute focal length, 86–88, 136 Guide-rails, 57–58 Guillot-Saguez, A., xi, 4–5, 7, 35, 145–46, 152, 178, 216 Half-plate. See Negative format Hardwich, T. Frederick, 160, 179, 189, 196, 200, 210, 216 Heat, effect on development, 164–65, 179

Hill, David Octavius. See Hill and Adamson Hill and Adamson, 6, 35, 183–84, 215, Color Plate II Hinges, 39, 66, 69, 71–72, 75. See also Book-cloth, Ribbon Hoff, Ruud, 119 Honey, 140, 147, 165 Horizontal positioning of camera, 41, 58–59, 63, 77 Horne and Thornthwaite, 6, 35, 216 Humbert de Molard, Louis-Adolphe, 145, 152, 166, 179 Identifying marks, 23–24, 33–34, 145–46, 170, 190, 193–94, 196 on film-holder and focusing screen, 23–24, 33–34 on paper, 145–46, 170, 190, 193–94, 196 Immersion, 139, 142, 146–49, 160, 162–63, 166, 171–76, 184, 188–89, 192–93, 194, 197, 202–04, 206–09. See also Flotation Iodized paper, keeping properties, 148. See also Iodizing Iodizing, 139, 142, 144, 145–51, 154, 171–73 procedure, 145–48, 171–73 Joining procedure. See Wood joining procedure Journal of the Royal Photographic Society, 126, 138, 216–17 Kaolin, 140, 157, 179, 185, 206. See also Replenishment Keith, Thomas, 177–78, 180 Kingslake, Rudolf, 119, 126, 136–38, 216 Lab equipment, 141, 186, 212 sources of supply, 212 Lactic acid, 204 Lactose, 140, 171–72 Landscape lens. See Lenses Large-format film, xi, 1 sources of supply, 212 Lateral reversal, 39, 118, 201 of daguerrean image, 39, 118 of negative, 201 Le Gray, Gustave, 5, 7, 35, 145, 147, 170, 172, 178–80, 216

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Lemon juice, 185, 195, 199–200. See also Citric acid Lens boards, 41, 47, 50–51, 58–60, 63, 66, 69, 74, 75–76, 81, 131–34 folding-camera lens board, 63, 66, 69, 74, 75–76, 133–34 sliding, box-camera lens board, 41, 47, 50–51, 58–60, 131–33 Lens caps, 61–62, 131, 135–36 Lens shapes, 82–86, 95–97, 100–02, 108, 110–13, 116, 118, 120–31 bi-concave, 82–83, 126–31 bi-convex, 82–84, 86, 96–97, 116, 121 negative meniscus, 82–84, 116 plano-concave, 82–84 plano-convex, 82–83, 95, 100–02, 105, 116, 118, 121–23, 125–31 positive meniscus, 82–86, 100–02, 108, 110–13, 118, 121–25 Lenses, x, 1, 3, 5–10, 23, 33, 37, 39, 41, 58–62, 64, 81–138. See also Lens shapes achromatic lenses, 94, 101–02, 104–05, 108, 110, 118, 121–22, 125, 127–28, 137 asymmetrical duplet, or portrait lens, xi, 7, 37, 81, 89, 91, 116–24, 125, 136–37 construction of, 122–25 configurations, 81–86 combined, 81–88 compound, 81–82, 85–86 simple, 81–83 distance between separated lens elements, 82, 85–86, 111–13, 122, 127 installation of lenses, 58–60, 75–76, 106, 131–34 folding-camera, 58–60, 133–34 sliding, box-camera, 75–76, 131–33 materials needed, 100 measuring lens diameter, 82, 103–04, 112–13, 119, 121 singlet, or landscape lens, x, 7, 37, 81, 88, 90–92, 97, 99, 100–08, 109, 111, 118–19, 121, 125, 136–37 new form, 101–02, 137 old form, 101–02, 137

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symmetrical duplet, or periscopic lens, 81, 88, 91–92, 108–16, 125, 136–37 symmetrical triplet, 81, 91–92, 125–31, 136, 138 tools needed, 99–100 Le Secq, Henri, 6, 35, 216 Light-metering, 159 Light-traps, 12, 18, 20, 24, 29, 31–32, 41, 64 Loupe. See Focusing loupe Luan plywood, 11, 18–20, 29–31, 45–48, 65–66, 69, 100, 131–34 method for cutting, 18, 29, 45, 65, 131–32 Milk, 33–34, 36, 140, 185, 204–06. See also Milk-serum, Whey agent in the serum process, 204–06 substitute for ground glass, 33–34, 36 Milk-serum, 142, 149, 184, 203. See also Rennet, Whey sources of supply, 214 Milk-sugar. See Lactose Miter box, 10, 12–14, 25, 42, 56, 65, 100, 104, 106, 113, 122, 128 Monckhoven, Désiré van, 7–9, 35, 83, 87, 93, 96, 98, 102–03, 111–12, 126, 136–38, 150, 178–79, 216–17 Mount Auburn Cemetery, xiii, 97, 99 Muslin, 197, 204–06. See also Coffee filters sources of supply, 214 Narrow-angle. See Angle of view Negative format, 2–10, 22, 33–34, 41, 63, 88–89, 103–04, 112–13, 121–22, 128 diagonal of, 3, 8–10, 88–89, 103, 112 evolution of, 4–9 layout on focusing screen, 22, 33–34 plate sizes, 5–11, 22–23, 37, 41, 104, 117, 120–22 difference between French and English plate sizes, 9 half-plate, 5–6, 8–10, 22–23, 120–22 quarter-plate, 5–6, 8–10, 22–23, 117, 120–22

whole-plate, 5–11, 22–23, 104, 117, 144, 163, 186–88 Negative lens. See Focal length Negative meniscus lens. See Lens shapes Negatives. See Paper negatives Nègre, Charles, 117 New form landscape lens. See Lenses Niépce, Nicéphore, 39, 79, 101, 137, 216 Normal-angle. See Angle of view Office Stationery, 142, 143–44, 187–88, 189. See also Paper Old form landscape lens. See Lenses Optical axis, 90–95, 97, 116 Optical components, 100, 104, 113, 122, 128 sources of supply, 211 Optical suplus. See Optical components Ottewill, Thomas, 63–64, 79 Painting, 20–21, 32, 56–57, 75, 133–34. See also Spray painting Paper, 141–44, 145–48, 151–54, 161–64, 167–78, 187–88, 189–99, 202–04, 206–09 sources of supply, 213 used for negatives, 141–44, 145–48, 151–54, 161–64, 167–77 used for positives, 187–88, 189–99, 202–04, 206–09 weight of, 142–44, 178, 187–88, 192, 204 Paper negatives, ix–x, 1–2, 23–24, 33–34, 37, 63, 139–80, 184, 197–98, 201, 206. See also Calotypes chemicals needed, 140–41 dry, waxed-paper process, 1, 5, 11, 24, 33, 37, 63, 139, 143, 170–78, 184, 206 materials needed, 141–45 wet-paper process, 1, 11, 37, 41, 139, 145–70, 184, 197–98 Parr, W.D., 166, 179, 217 Pélegry, Arsène, 24, 35–36, 217 Percentage solutions, preparation of, 145 Periscopic lens. See Lenses Perspective correction, 4, 34, 62– 63

Petzval portrait lens, xi, 116–20, 137–38 Photographe à verres combinés, xi, 116, 118–20, 122 Photographic Notes, 180, 182, 195, 200, 209–10, 216–17 Pincushion distortion. See Aberrations Pinhole photography, ix–x, 37, 79, 217 Plano-concave lens. See Lens shapes Plano-convex lens. See Lens shapes Plate sizes. See Negative format Platform base. See Cameras Polaroid SX-70, 38 Porta, Giovanni Battista della, 37, 101 Portrait lens. See Lenses Positive lens. See Focal length Positive meniscus lens. See Lens shapes Potassium bromide, 140, 147, 150–51, 172 Potassium iodide, 139–40, 146–47, 151, 163, 166, 172, 175, 185, 197 Prince Albert, 183 Printing-out, xii, 181–84, 209, Color Plate II Purifying sensitizing solutions. See Replenishment Putty, 11, 15, 17, 27, 72 PVC, 95, 100, 104, 106, 113, 122–23, 128, 130, 132–35 Pythagorean theorem, 10, 88 Quarter-plate. See Negative formats Rennet, 185, 204–05. See also Milkserum, Whey Sources of supply, 214 Replenishment, 156–57, 175, 179, 198, 206. See also Kaolin Ribbon, 40, 66, 69, 71–72, 75. See also Book-cloth, Hinges Ross, Andrew, 7, 126, 138 Rubylith film, 11, 22, 141, 153, 155, 161 Safelight, 142, 150, 152–53, 161–62, 199, 201–02, 206, 208. See also Bug-light Safety equipment, 10, 15, 20, 27, 32, 56, 75, 140–41, 145, 150, 160–61, 172, 174, 177, 185, 197, 208 sources of supply, 212

Safety precautions, 15, 20, 27, 32, 52, 56, 75, 140–41, 145, 150, 160–61, 163, 172, 174–75, 177–78, 197, 185, 206, 208 Salt printing, xii, 189–203, 209–10. See also Serum process chemicals needed, 184–85 effect of using different types of salt, 196–97, Color Plate VII materials needed, 185–89 procedure, 189–203 Salted paper, keeping properties, 195. See also Salt printing Sanding wood, 12, 15–20, 24–25, 27–30, 32, 41, 48–49, 52, 57, 64, 72, 75, 132 Saturated solutions, 164–65, 166, 179, 200 Sensitizing, 1–2, 5, 139, 148, 150–58, 166, 170, 174–78, 184, 186, 188–89, 195, 197–200, 204, 206–07, 210, Color Plates VIII–IX dry, waxed-paper process, 173, 174–76 salt printing 189, 195, 197–200, 204 serum process 188, 204, 206–07 wet-paper process, 148, 150–57 Serum process, 184, 188, 203–09, 210. See also Salt printing procedure, 204–09 Sheet film. See Large-format film Sheet metal, 211. See also Brass shimstock sources of supply, 211 Silver bromide, 150 Silver chloride, 184, 194, 207 Silver iodide, 139, 148, 150, 162, 164, 173 Silver nitrate, 139–40, 145, 150, 152, 156–57, 159, 161–63, 166, 174–78, 182, 184–85, 197–200, 207. See also Sensitizing Simple lens. See Lenses Singlet lens. See Lenses Sizing 139, 142, 143, 146, 148–49, 172, 184, 188, 189–93, 196–97, 203–04 gelatin, 189, 196 procedures, 189–93 flotation, 189–92 immersion, 192–93 starch, 142–43, 148, 172, 189–93

Skim milk. See Milk Sliding box-camera, historical designs, 38–39, 41–42, 78–79. See also Cameras Sodium acetate, 166, 179, 185, 208 Sodium chloride, 140, 147, 181, 184–85, 195–99, 203, 206, 208, 210 Sodium citrate, 185, 196 Sodium sulfite, 163, 203, 209 Sodium thiosulfate, 139–40, 159, 160, 162, 177, 185, 203–04, 209 Spectral sensitivity, 94, 145, 150, 159 Spherical aberration. See Aberrations Spray painting, 104, 113, 124, 128. See also Painting Stains, 1–2, 4, 11, 143–44, 146, 148, 150–51, 155, 156–57, 159, 165, 167, 172–73, 175, 188, 194, 198–99, Color Plate IX Starch. See Sizing Steinheil, Adolph, 110 Steinheil’s method for determining effective aperture. See Aperture Steinheil’s Periskop. See Lenses Stops. See Aperture Sugar, 140, 165, 179 Sutton, Thomas, xiii, 6–7, 35, 110, 117–18, 120–21, 125–27, 137–38, 179, 182–84, 189, 195, 197, 200, 203, 207, 210, 215, 217 SX-70. See Polaroid SX-70 Symmetrical duplet. See Lenses Symmetrical triplet. See Lenses Système allemand, 119–20 Talbot, William Henry Fox, xi, 3–6, 11, 34–35, 139, 145, 183 Taylor, Dennis, 126 35mm photography, ix Time of day, as effecting exposure. See Exposure Toning, 182, 184, 195, 200, 208–09, Color Plate X Transmittance, 86, 91–92, 136 Tripod, use of, 41, 57–59, 62–63, 75–77 Valicourt, E. de, 3, 120, 137–38, 152, 160, 179, 195, 200, 204, 210, 217 Van Monckhoven, Désiré. See Monckhoven, Désiré van

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Velvet. See Dark-cloth Vermeer, Jan, 38 Vertical positioning of camera, 41, 57–59, 76–77 View-Cameras. See Cameras Vignetting, 103, 111, 113, 121–22 Vinyl adhesive caulk, 40, 52, 100, 133–34. See also Contact cement, Glue Washing aid, 163–164, 203, 209. See also Fixer remover Washing negatives and positive prints, 163–64, 177, 184, 188, 203, 209 Water. See Distilled water

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Watermarks, 142–43, 187 Waxing procedure, 167–71, 173, 177 dry, waxed-paper process, 170–71, 173, 177 wet-paper process, 167–70 Weather, as affecting exposure. See Exposure Wedgwood, Thomas, 38, 216 Wet-collodion process, 3, 6–8, 179 Wet-paper process. See Paper negatives Wet-process film-holder. See Filmholders Wet strength of paper, 142–44, 187–88

Whey, 142, 146–47, 149, 159, 171–72, 184, 203–06, 210. See also Milk-serum, Rennet procedure for making whey, 204–06, 210 Whole-plate. See Negative format Wide-angle. See Angle of view Wide-field. See Angle of view Wollaston, William Hyde, 101, 137 Wood. See Basswood frame-stock Wood, John Muir, 6, 35 Wood joining procedure, 76–78 Woodman, Clarence, 88–89 Zahn, Johann, 38